Skillful Three-Dimensional Printing

ABSTRACT

The present disclosure various apparatuses, and systems for 3D printing. The present disclosure provides three-dimensional (3D) printing methods, apparatuses, software and systems for a step and repeat energy irradiation process; controlling material characteristics and/or deformation of the 3D object; reducing deformation in a printed 3D object; and planarizing a material bed.

CROSS-REFERENCE

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 62/265,817, filed on Dec. 10, 2015, and U.S. Provisional PatentApplication Ser. No. 62/317,070, filed on Apr. 1, 2016, each of which isentirely incorporated herein by reference.

BACKGROUND

Three-dimensional (3D) printing (e.g., additive manufacturing) is aprocess for making a three-dimensional (3D) object of any shape from adesign. The design may be in the form of a data source such as anelectronic data source, hard copy, or physical structure (e.g., physicalmodel). The hard copy may be a two-dimensional representation of a 3Dobject. The data source may be an electronic 3D model. 3D printing maybe accomplished through an additive process in which successive layersof material are laid down one on top of each other to formed a layered3D object (e.g., of hardened material). This process may be controlled(e.g., computer controlled, and/or manually controlled). For example, a3D printer can be an industrial robot.

3D printing can generate custom parts quickly and efficiently. A varietyof materials can be used in a 3D printing process including elementalmetal, metal alloy, ceramic, elemental carbon, or a polymeric material.In a typical additive 3D printing process, a first material-layer isformed, and thereafter, successive material-layers (or parts thereof)are added one by one, wherein each new material-layer is added on apre-formed material-layer, until the entire designed three-dimensionalstructure (3D object) is materialized.

3D models may be created utilizing a computer aided design package orvia 3D scanner. The manual modeling process of preparing geometric datafor 3D computer graphics may be similar to plastic arts, such assculpting or animating. 3D scanning is a process of analyzing andcollecting digital data on the shape (e.g., and appearance) of a realobject. Based on this data, 3D models of the scanned object can beproduced. The 3D models may include computer-aided design (CAD).

Many additive processes are currently available. They may differ in themanner layers are deposited to create the materialized structure. Theymay vary in the material or materials that are used to generate thedesigned structure. Some methods melt or soften material to produce thelayers.

SUMMARY

At times, the printed three-dimensional (3D) object may bend, warp,roll, curl, or otherwise deform during and/or after the 3D printingprocess. Auxiliary supports may be inserted to circumvent suchdeformation. These auxiliary supports may be subsequently removed fromthe printed 3D object to produce a requested 3D product (e.g., 3Dobject). The presence of auxiliary supports may increase the cost and/ortime required to manufacture the 3D object. At times, the requirementfor the presence of auxiliary supports hinders (e.g., prevent) formationof a desired 3D object. For example, the presence of auxiliary supportmay hinder formation of certain hanging structures (e.g., ledges) and/orcavities as part of the desired 3D object. The requirement for thepresence of auxiliary supports may place constraints on the design of 3Dobjects, and/or on their respective materialization. In someembodiments, the inventions in the present disclosure facilitate thegeneration of 3D objects with a reduced degree of deformation. In someembodiments, the inventions in the present disclosure facilitate thegeneration of 3D objects that are fabricated with diminished number(e.g., absence) of auxiliary supports (e.g., without auxiliarysupports). In some embodiments, the inventions in the present disclosurefacilitate generation of 3D objects with diminished amount of designand/or fabrication constraints (referred to herein as “constraint-less3D object”). In some embodiments, a layer forming the 3D object isfabricated using large tiles. The tiles may be formed by hatching thetile interior with a small diameter energy beam (e.g., scanning energybeam). The tiles may be formed by irradiating a substantially stationarylarge diameter energy beam (e.g., tiling energy flux). The tiles may beformed with a low power energy beam that, in some examples, penetrates aportion of a previously formed 3D object layers (e.g., that is disposedbelow the irradiated portion), and allows these layers to reach anelevated temperature (i) above the solidus temperature and below theliquidus temperature of the bottom skin layer material (e.g., at theliquefying temperature), or (ii) at which a material in the bottom skinlayer plastically yields. For example, the previously formed layer canbe a bottom skin layer of the entire 3D object, of a hanging structureof the 3D object, or of a crevice ceiling within the 3D object. Theenergy beam forming the tile can be a defocused beam. The presentdisclosure delineates methods for forming such a beam using an opticaldiffuser.

In an aspect described herein are methods, systems, software, and/orapparatuses for generating a 3D object with a reduced degree ofdeformation (e.g., substantially non-deformed). The 3D object can bedevoid of one or more auxiliary supports. The 3D object can be devoid ofa mark indicating the prior presence of one or more auxiliary supports.The 3D object can be an extensive 3D object. The 3D object can be alarge 3D object. The 3D object may comprise a large hanging structure(e.g., wire, ledge, or shelf). Large may be a 3D object having afundamental length scale (FLS) of at least about 10 centimeters.

Sometimes, it is desired to control the microstructure of a 3D object toform a specific type of a microstructure (e.g., in at least a portion ofthe 3D object). Occasionally, it is desired to fabricate a 3D objectwith varied materials and/or material microstructures in one or more(e.g., specific) portions of the 3D object. For example, there may be arequirement for a motor comprising a dense center, and porous blades.The present disclosure describes formation of such desired 3D objects.In some instances, it is desired to control the way in which at least aportion of a layer of hardened material is formed (e.g., which mayaffect the material properties of that portion). The layer of hardenedmaterial may comprise at least one melt pool. In some instances, it maybe desired to control one or more characteristics of that melt pool.

In some instances, the 3D object deforms during the 3D printing process,and protrudes from the material bed. Such phenomenon may make itdifficult to form a 3D object that will adhere the customer requests.Such phenomenon may also burden the deposition and/or leveling of aplanarized layer of pre-transformed (e.g., particulate) material. Thepresent disclosure delineates methods and apparatuses that cope with aprotruding object from an exposed surface of a material bed. Forexample, by using a material removal member that planarizes the exposedsurface material bed without contacting it, for example, using a forcethat directs (e.g., attracts and/or maneuvers) the pre-transformedmaterial and/or debris away from the target surface.

At times, it is desired to remove any remainder of the material bed thatdid not form the 3D object, from the printed 3D object, under the sameatmosphere in which it was printed. For example, when thepre-transformed material is sensitive to oxygen and/or water and/orotherwise highly reactive in the ambient environment. The presentdisclosure delineates methods and apparatuses that allow cleaning of the3D object from a material be remainder in the same environment in whichthe 3D object is formed.

In another aspect, a method for printing a three-dimensional objectcomprises: (a) providing a material bed comprising a pre-transformedmaterial; (b) irradiating an exposed surface of the material bed usingan energy beam directed at a first position of the exposed surface thatis substantially stationary during a first time-period of at least onemillisecond, to transform the pre-transformed material at the firstposition to a transformed material to form a first tile; (c) translatingthe energy beam to a second position of the exposed surface, whichsecond position is different from the first position, wherein the energybeam is translated without transforming the pre-transformed material;and (d) irradiating the exposed surface of the material bed at thesecond position with the energy beam that is substantially stationary atthe second position during a second time-period of at least about onemillisecond, to transform the pre-transformed material at the secondposition to a transformed material to form a second tile.

The energy beam may have a power density of at most about 8000 W/mm².The first time-period can be substantially equal to the secondtime-period. The first time-period can be at least about one millisecond(msec). The energy beam may be translated during a third time-period ofat least about 1 msec, 10 msec, 50 msec, 250 msec, or 500 msec. Thecross section of the energy beam can be at least about 0.1 millimetersquared (mm²), or 0.2. The diameter of the energy beam can be at leastabout 300 micrometers. The distance between the first position and thesecond position can be at least about 100 micrometers, 200 micrometers,or 250 micrometers. The horizontal cross section of the second tile mayat least contact the horizontal cross section of the first tile. Contactmay comprise overlap. The horizontal cross section of the second tilemay at least partially overlap the horizontal cross section of the firsttile. The second tile may overlap at least about 40% of the first tile.The horizontal cross section of the second tile may (e.g., completely)overlap the horizontal cross section of the first tile by at least about40%. The method may further comprise dispensing a layer of thepre-transformed material by removing an excess of pre-transformedmaterial from the exposed surface of the material bed (e.g., by using agas flow and optionally (e.g., cyclonically) separating thepre-transformed material from the gas flow). The second tile may atleast contact the first tile. The second tile may at least partiallyoverlap the first tile. The overlap can be by at least about 40%. Theoverlap can be any value of the horizontal cross section overlapmentioned herein.

The pre-transformed material may be at least one member selected fromthe group consisting of elemental metal, metal alloy, ceramic, and anallotrope of elemental carbon. Transform can comprise fuse. Fuse cancomprise sinter or melt. Melt can comprise completely melt. The 3Dprinting may be at an ambient pressure. The 3D printing may be at anatmospheric pressure. The 3D printing may be at an ambient temperature.The 3D printing may be at room temperature. The 3D printing may cancomprise additive manufacturing.

In another aspect, a method for printing a three-dimensional objectcomprises: (a) providing a material bed comprising a pre-transformedmaterial; (b) irradiating an exposed surface of the material bed usingan energy beam directed at a first position of the exposed surface thatis substantially stationary during a first time-period to transform thepre-transformed material at the first position to a transformed materialto form a first tile, which energy beam has a power density of at mostabout 8000 Watts per millimeter squared; (c) translating the energy beamto a second position of the exposed surface, which second position isdifferent from the first position, which energy beam is translatedwithout transforming the pre-transformed material; and (d) irradiatingthe exposed surface of the material bed at the second position with theenergy beam that is substantially stationary at the second positionduring a second time-period, to transform the pre-transformed materialat the second position to a transformed material to form a second tile.

The power density may be at most 5000 W/mm². The energy beam may betranslated within a time-period of at least about 1 millisecond. Theenergy beam may be translated within a time-period of at least about onemillisecond (msec), 10 msec, 50 msec, 250 msec, or 500 msec. Thetranslation can be during at least about 1 msec, 10 msec, 50 msec, 250msec, or 500 msec. The cross section of the energy beam can be at leastabout 0.1 millimeter squared (mm²), or 0.2. The diameter of the energybeam can be at least about 300 micrometers, 500 micrometers, or 600micrometers. The distance between the first position and the secondposition can be at least about 100 micrometers, 200 micrometers, or 250micrometers. The second tile may at least contact (e.g., contact andoverlap) the first tile.

Substantially stationary may comprise spatial oscillations that aresmaller than the FLS (e.g., diameter) of the energy beam.

In another aspect, a method for printing a three-dimensional objectcomprises: providing a material bed comprising a pre-transformedmaterial; (c) irradiating an exposed surface of the material bed using adefocused energy beam directed at a first position of the exposedsurface that is substantially stationary during a first time-period totransform the pre-transformed material at the first position to atransformed material to form a first tile; (d) translating the defocusedenergy beam to a second position of the exposed surface, which secondposition is different from the first position, which defocused energybeam is translated without transforming the pre-transformed material;and (e) irradiating the exposed surface of the material bed at thesecond position with the defocused energy beam that is substantiallystationary at the second position during a second time-period totransform the pre-transformed material in the second position to atransformed material to form a second tile.

A diameter of the defocused energy beam can be at least about 300micrometers. The at least one of the first time-period and the secondtime-period can be at least about 1 millisecond. The first time-periodcan be (e.g., substantially) equal to the second time-period. The energybeam may translate within a third time-period of at least about 1millisecond. A distance between the first position and the secondposition can be at least 100 micrometers. The second tile may at leastcontact the first tile. The second tile may at least partially overlapthe first tile. The overlap can be by at least about 40%. The overlapcan be any value of the horizontal cross section overlap mentionedherein. The first time-period can be at least about one millisecond(msec), 10 msec, 50 msec, 250 msec, or 500 msec. The translation can beduring at least about 1 msec, 10 msec, 50 msec, 250 msec, or 500 msec.The cross section of the defocused energy beam can be at least about 0.1millimeter squared (mm²), or 0.2. The diameter of the defocused energybeam can be at least about 300 micrometers. The distance between thefirst position and the second position can be at least about 250micrometers. The power density of the defocused energy beam may be atmost about 6000 W/mm².

In another aspect, a method for printing a three-dimensional objectcomprises: providing a material bed comprising a pre-transformedmaterial; directing an energy beam to an optical diffuser to generate adiffused energy beam; (c) irradiating an exposed surface of the materialbed using the diffused energy beam directed at a first position of theexposed surface that is substantially stationary during a firsttime-period to transform the pre-transformed material at the firstposition to a transformed material to form a first tile; (d) translatingthe diffused energy beam to a second position of the exposed surface,which second position is different from the first position, whichtranslating is without transforming the pre-transformed material; and(e) irradiating the exposed surface of the material bed at the secondposition with the diffused energy beam that is substantially stationaryat the second position during a second time-period to transform thepre-transformed material in the second position to a transformedmaterial to form a second tile.

The optical diffuser may distort the wave front of the energy beam. Theoptical diffuser may comprise a microlens (e.g., array) or a digitalmask. The optical diffuser can be comprised in a diffuser wheel. Adiameter of the diffused energy beam can be at least about 300micrometers. The at least one of the first time-period and the secondtime-period can be at least about 1 millisecond. The first time-periodcan be (e.g., substantially) equal to the second time-period. Thetranslation can be during at least about 1 millisecond. A distancebetween the first position and the second position can be at least 100micrometers. The second tile may at least contact the first tile. Thesecond tile may at least partially overlap the first tile. The overlapcan be by at least about 40%. The overlap can be any value of thehorizontal cross section overlap mentioned herein. The first time-periodcan be at least about one millisecond (msec), 10 msec, 50 msec, 250msec, or 500 msec. The translation can be during at least about 1 msec,10 msec, 50 msec, 250 msec, or 500 msec. The cross section of thediffused energy beam can be at least about 0.1 millimeter squared (mm²),or 0.2. The diameter of the energy beam can be at least about 300micrometers. The distance between the first position and the secondposition can be at least about 100 micrometers. The power density of thediffused energy beam may be at most about 7000 W/mm².

In another aspect, a system for printing a three-dimensional objectcomprises: a container configured to enclose a material bed comprisingan exposed surface and a pre-transformed material; an energy sourceconfigured to generate an energy beam that transforms at least a portionof the exposed surface to a transformed material as part of thethree-dimensional object, wherein the energy source is disposed adjacentto the material bed; and one or more controllers operatively coupled tothe material bed, and the energy source, which one or more controllersdirect the energy beam to: (i) irradiate the exposed surface of thematerial bed at a first position that is substantially stationary duringa first time-period that is at least one millisecond and transform thepre-transformed material in the first position to a transformed materialto form a first tile, (ii) translate the energy beam to a secondposition in the exposed surface, which second position is different fromthe first position, which translate is without transforming thepre-transformed material; and (iii) irradiate the exposed surface of thematerial bed at the second position with the energy beam that issubstantially stationary at the second position during a secondtime-period that is at least about one millisecond to transform thepre-transformed material in the first position to a transformed materialto form a second tile that overlaps the first tile.

In another aspect, a system for printing a three-dimensional objectcomprises: a container configured to enclose a material bed comprisingan exposed surface and a pre-transformed material; an energy sourceconfigured to generate an energy beam that transforms at least a portionof the exposed surface to a transformed material as part of thethree-dimensional object, which energy beam has a power density of atmost about 8000 Watts per millimeter squared; wherein the energy sourceis disposed adjacent to the material bed; and one or more controllersoperatively coupled to the material bed, and the energy source, whichone or more controllers direct the energy beam to: (i) irradiate theexposed surface of the material bed at a first position that issubstantially stationary during a first time-period and transform thepre-transformed material in the first position to a transformed materialto form a first tile, (ii) translate the energy beam to a secondposition in the exposed surface, which second position is different fromthe first position, which translate is without transforming thepre-transformed material; and (iii) irradiate the exposed surface of thematerial bed at the second position with the energy beam that issubstantially stationary at the second position during a secondtime-period to transform the pre-transformed material in the firstposition to a transformed material to form a second tile that overlapsthe first tile.

In another aspect, a system for printing a three-dimensional objectcomprises: a container configured to enclose a material bed comprisingan exposed surface and a pre-transformed material; a defocused energysource configured to generate the energy beam that transforms at least aportion of the material bed to a transformed material as part of thethree-dimensional object, wherein the energy source is disposed adjacentto the material bed; and one or more controllers operatively coupled tothe material bed, the energy source, and the optical diffuser, which oneor more controllers direct the defocused energy beam to (i) irradiatethe exposed surface of the material bed at a first position that issubstantially stationary during a first time-period to transform thepre-transformed material in the first position to a transformed materialto form a first tile; (ii) translate a second position in the exposedsurface, which second position is different from the first position,which translate is without transforming the pre-transformed material;and (iii) irradiate the exposed surface of the material bed at thesecond position with the energy beam that is substantially stationary atthe second position during a second time-period to transform thepre-transformed material in the first position to a transformed materialto form a second tile. For example, the first tile at least contacts thesecond tile.

In another aspect, a system for printing a three-dimensional objectcomprises: a container configured to enclosure a material bed comprisingan exposed surface and a pre-transformed material; an optical diffuserconfigured to diffuse a first cross section of an energy beam to form asecond cross section that is diffused relative to the first crosssection; an energy source configured to generate the energy beam thattransforms at least a portion of the material bed to a transformedmaterial as part of the three-dimensional object, wherein the energysource is disposed adjacent to the material bed; and one or morecontrollers operatively coupled to the material bed, the energy source,and the optical diffuser, which one or more controllers (e.g.,collectively or individually) direct (I) the energy beam having thefirst cross section to travel through the optical diffuser to diffusethe first cross section and form the second cross section (II) theenergy beam having the second cross section to (i) irradiate the exposedsurface of the material bed at a first position that is substantiallystationary during a first time-period to transform the pre-transformedmaterial in the first position to a transformed material to form a firsttile; (ii) translate a second position in the exposed surface, whichsecond position is different from the first position, which translate iswithout transforming the pre-transformed material; and (iii) irradiatethe exposed surface of the material bed at the second position with theenergy beam that is substantially stationary at the second positionduring a second time-period to transform the pre-transformed material inthe first position to a transformed material to form a second tile thatoverlaps the first tile.

In another aspect, a method for printing a three-dimensional objectcomprises: (A) providing a first pre-transformed material to a bottomskin layer of hardened material that is disposed above a platform, whichbottom skin layer is part of the three-dimensional object; and (B) usingan energy beam to: (I) transform the pre-transformed material to a firstportion of transformed material as part of the three-dimensional object,which first portion has a first lateral cross section, (II) increase atemperature of a second portion that (a) is part of the bottom skinlayer and (b) has a second lateral cross section that at least partiallyoverlaps the first lateral cross section, to at least a targettemperature value that is at least one of (i) above the solidustemperature and below the liquidus temperature of the material of thebottom skin layer, and (ii) at a temperature at which the material ofthe bottom skin layer in the second portion plastically yields.

The bottom skin layer of hardened material may be disposed above theplatform along a direction perpendicular to the platform. Above can bedirectly above (e.g., such that the bottom skin layer contacts theplatform). Providing can comprise streaming. The transformation can beabove or at the bottom skin layer. The transform can be prior to contactformation between the bottom skin layer and the transformed material.The transformation can be at the bottom skin layer. The center of thefirst cross section can be above (e.g., aligned with) the second crosssection. Above can be along the direction perpendicular to the platform.Above can be in the direction opposing the platform. Above can be in thedirection opposite to the gravitational center. Increase can compriseusing closed loop or open loop control. Control can comprise temperaturecontrol. Increase can comprise using feedback or feed-forward control.The control can comprise using a graphical processing unit (GPU),system-on-chip (SOC), application specific integrated circuit (ASIC),application specific instruction-set processor (ASIPs), programmablelogic device (PLD), or field programmable gate array (FPGA). Increasecan comprise using a simulation (e.g., The temperature of the secondportion may be increased with the aid of a simulation). The simulationcan comprise a temperature and/or mechanical simulation of the 3Dprinting of the 3D object. The simulation may comprise thermo-mechanicalsimulation. The simulation can comprise a material property of the 3Dobject (e.g., that is requested by a user). The thermo-mechanicalsimulation can comprise elastic or plastic simulation. The temperatureof the second portion is increased with the aid of a graphicalprocessing unit (GPU), system-on-chip (SOC), application specificintegrated circuit (ASIC), application specific instruction-setprocessor (ASIPs), programmable logic device (PLD), or fieldprogrammable gate array (FPGA).

In another aspect, a method for printing a three-dimensional objectcomprises: (A) providing a material bed comprising a pre-transformedmaterial and a bottom skin layer of hardened material, which materialbed is disposed above a platform, wherein the bottom skin layer is partof the three-dimensional object, wherein at least a fraction of thepre-transformed material is disposed above the bottom skin layer; and(B) irradiating a first portion of the planar layer with the energy beamto: (I) transform the pre-transformed material in the first portion to atransformed material as part of the three-dimensional object, whichfirst portion has a first lateral cross section; (II) increase atemperature of a second portion that (a) is part of the bottom skinlayer and (b) has a second lateral cross section that overlaps the firstlateral cross section, to at least a target temperature value that is atleast one of (i) above the solidus temperature and below the liquidustemperature of the material of the bottom skin layer, and (ii) at atemperature at which the material of the bottom skin layer in the secondportion plastically yields.

The at least a fraction can comprise a planar exposed surface of thematerial bed. Above can be along a direction opposite to the platform.Above can be directly above such that the bottom skin layer contacts theplatform. Transform can be above or at the bottom skin layer. Transformcan be at the bottom skin layer. The center of the first cross sectioncan be above the second cross section. Above can be along the directionperpendicular to the platform. Above can be in the direction opposingthe platform. Above can be in the direction opposite to thegravitational center. Increase can comprise using closed loop or openloop temperature control (e.g., the temperature of the second portioncan be increased using closed loop or open loop control). Increase cancomprise using feedback or feed-forward control (e.g., the temperatureof the second portion can be increased using feedback or feed-forwardcontrol). Increase can comprise using a simulation. The simulation cancomprise a temperature or mechanical simulation of the 3D printing. Thesimulation may comprise thermo-mechanical simulation (e.g., of the 3Dprinting and/or of the 3D object during its fabrication in the 3Dprinting). The simulation can comprise a material property of therequested 3D object. The mechanical simulation can comprise elastic orplastic simulation. The control can comprise using a graphicalprocessing unit (GPU), system-on-chip (SOC), application specificintegrated circuit (ASIC), application specific instruction-setprocessor (ASIPs), programmable logic device (PLD), or fieldprogrammable gate array (FPGA). The disposing may comprise dispensing alayer of the pre-transformed material (e.g., by removing an excess ofpre-transformed material from the exposed surface of the material bedusing a gas flow and optionally cyclonically separating thepre-transformed material from the gas flow). Providing the material bedmay comprise dispensing a layer of the pre-transformed material byremoving an excess of pre-transformed material from the exposed surfaceof the material bed using gas flow and cyclonically separating thepre-transformed material from the gas flow.

In another aspect, a method for printing a three-dimensional objectcomprises: (a) providing a pre-transformed material to a bottom skinlayer of hardened material disposed above a platform, wherein the bottomskin layer is part of the three-dimensional object; (b) using an energybeam to transform a portion of the pre-transformed material to a portionof transformed material disposed above the bottom skin layer; and (c)setting at least one characteristic of the energy beam such that atemperature of the three-dimensional object at the bottom skin layerbelow the portion of transformed material is at least one of (i) abovethe solidus temperature and below the liquidus temperature of thematerial of the bottom skin layer, and (ii) at temperature at which amaterial of the bottom skin layer plastically yields.

The transformed material can be a melt pool. The method may furthercomprise after operation (c), repeating at least operation (b). Themethod may further comprise repeating operation (b) subsequent tooperation (c). Below the portion can be along a direction perpendicularto the platform and in the direction towards the platform (e.g., thebottom skin layer may be below the portion of transformed along adirection perpendicular to the platform). The at least onecharacteristics comprises power density, cross sectional area,trajectory, speed, focus, energy profile, dwell time, intermission time,or fluence of the energy beam. The disposing can comprise dispensing alayer of the pre-transformed material by removing an excess ofpre-transformed material from the exposed surface of the material bedusing a gas flow and cyclonically separating the pre-transformedmaterial from the gas flow. Above can be directly above such that thebottom skin layer contacts the platform. The providing can comprisestreaming. The transform can be above or at the bottom skin layer. Thetransform can be prior to contact formation between the bottom skinlayer and the transformed material. The transform can be at the bottomskin layer. The center of the first cross section can be above thesecond cross section. Above can be along the direction perpendicular tothe platform. Above can be in the direction opposing the platform. Abovecan be in the direction opposite to the gravitational center. Increasecan comprise using closed loop or open loop (e.g., temperature) control.The control can be of at least one characteristics of the energy beam(e.g., as disclosed herein). Increase can comprise using feedback orfeed-forward control. Increase can comprise using a simulation. Thesimulation can comprise a temperature or mechanical simulation of the 3Dprinting. The simulation may comprise thermo-mechanical simulation. Thesimulation can comprise a material property of the requested 3D object.The thermo-mechanical simulation can comprise elastic or plasticsimulation. The control can comprise using a graphical processing unit(GPU), system-on-chip (SOC), application specific integrated circuit(ASIC), application specific instruction-set processor (ASIPs),programmable logic device (PLD), or field programmable gate array(FPGA).

In another aspect, a method for printing a three-dimensional objectcomprises: (a) providing a material bed comprising a pre-transformedmaterial and a bottom skin layer of hardened material, which materialbed is disposed above a platform, wherein the bottom skin layer is partof the three-dimensional object, wherein at least a fraction of thepre-transformed material is disposed above the bottom skin layer,wherein above is along a direction opposite to the platform; (b) usingan energy beam to transform a portion of at least a fraction of thepre-transformed material into a transformed material as part of thethree-dimensional object; and (c) setting at least one characteristic ofthe energy beam such that a temperature of the three-dimensional objectat the bottom skin layer below the portion is at least one of (i) abovethe solidus temperature and below the liquidus temperature of the bottomskin layer material, and (ii) at temperature at which a material in thebottom skin layer plastically yields.

The method may further comprise after operation (c), repeating at leastoperation (b). Below the portion can be along a direction perpendicularto the platform and in the direction towards the platform. The at leasta fraction can comprise a planar exposed surface of the material bed.The bottom skin layer can be a first formed layer of (i) thethree-dimensional object, (ii) a hanging structure of thethree-dimensional object, or (iii) a cavity ceiling of thethree-dimensional object. The bottom skin layer may have a sphere ofradius XY on a bottom surface of the bottom skin layer, wherein an acuteangle between the straight line XY and the direction normal to theaverage layering plane of the bottom skin layer can be in the range fromabout 45 degrees to about 90 degrees. The first formed layer of thethree-dimensional object can be disconnected from the platform duringthe 3D printing. The first formed layer of the three-dimensional objectcan comprise auxiliary support that can be disconnected from (e.g., notanchored to) the platform during the 3D printing. During the 3Dprinting, the first formed layer of the three-dimensional object maycomprise auxiliary support features that are spaced apart by 2millimeters or more. The hanging structure of the three-dimensionalobject may comprise at least one side that is not connected to (e.g.,disconnected from) the three-dimensional object or to the platform. Thehanging structure of the three-dimensional object may comprise at leasttwo sides that are not connected to (e.g., disconnected from) thethree-dimensional object or to the platform. The hanging structure ofthe three-dimensional object may comprise at least three sides that arenot connected to (e.g., disconnected from) the three-dimensional objector to the platform. The hanging structure can comprise auxiliary supportthat is not anchored to the platform. The hanging structure can compriseauxiliary support features that are spaced apart by 2 millimeters ormore. The cavity ceiling of the three-dimensional object may comprise atleast one side that is not connected to the three-dimensional object orto the platform. The cavity ceiling of the three-dimensional object maycomprise at least two sides that are not connected to thethree-dimensional object or to the platform. The cavity ceiling of thethree-dimensional object may comprise at least three sides that are notconnected to the three-dimensional object or to the platform. The cavityceiling comprises auxiliary support that is not anchored to theplatform. The hanging structure comprises auxiliary support featuresthat are spaced apart by 2 millimeters or more.

In another aspect, a system for printing a three-dimensional objectcomprises: a platform and a bottom skin layer of hardened material thatis a part of the three-dimensional object, wherein the bottom skin layeris disposed above the platform; a material dispenser configured todispense a pre-transformed material towards the platform though anopening, wherein the material dispenser is disposed adjacent to theplatform; an energy source configured to generate an energy beam thattransforms at least a portion of the pre-transformed material in at oradjacent to the platform, wherein the energy source is disposed adjacentto the platform; and one or more controllers operatively coupled to thematerial bed, the material dispenser, and the energy source, which oneor more controllers are individually or collectively programmed to: (A)direct the material dispenser to dispense a pre-transformed material ator above the bottom skin layer, and (B) direct the energy beam to (I)transform the pre-transformed material and form a first portion at orabove the bottom skin layer (e.g., which above is in the directionopposite to the platform), which first portion has a first lateral crosssection; and (II) increase a temperature of a second portion that (a) ispart of the bottom skin layer and (b) has a second lateral cross sectionthat at least partially overlaps the first lateral cross section, to atleast a target temperature value that is at least one of (i) above thesolidus temperature and below the liquidus temperature of the materialof the bottom skin layer, and (ii) at a temperature at which thematerial of the bottom skin layer in the second portion plasticallyyields.

The first portion can be above the bottom skin layer along a directionperpendicular to the platform. Above can be directly above such that thebottom skin layer contacts the platform. Above can be indirectly abovesuch that the bottom skin layer does not connect and/or contact theplatform. The bottom skin layer can be separated from the platform bythe pre-transformed material. The bottom skin layer can be separatedfrom the platform by a layer of the pre-transformed material. The bottomskin layer may float anchorlessly above the platform. The bottom skinlayer can comprise one or more auxiliary supports. The one or moreauxiliary supports can be anchored to the platform. The one or moreauxiliary supports may float anchorlessly above the platform. Thedispenses in operation (b) can comprise streams. The control cancomprise using closed loop or open loop control. The increase cancomprise using feedback or feed-forward control. The control cancomprise using a simulation. The one or more controllers can beindividually or collectively programmed to direct the energy beam toincrease the temperature of the second portion using a simulation. Thesimulation can comprise a temperature or mechanical simulation of the 3Dprinting. The simulation may comprise thermo-mechanical simulation. Thesimulation can comprise a material property of the requested 3D object.The thermo-mechanical simulation can comprise elastic or plasticsimulation. The one or more controllers can be individually orcollectively programmed to direct the energy beam to increase thetemperature of the second portion using a graphical processing unit(GPU), system-on-chip (SOC), application specific integrated circuit(ASIC), application specific instruction-set processor (ASIPs),programmable logic device (PLD), or field programmable gate array(FPGA). The method may further comprising a cyclonic separator toseparate any excess of pre-transformed material that did not transformto form the three-dimensional object.

In another aspect, a system for printing a three-dimensional objectcomprises: a container configured to support a material bed comprisingan exposed surface, a pre-transformed material, and a bottom skin layerof hardened material, wherein at least a fraction of the pre-transformedmaterial is disposed above the bottom skin layer, wherein the bottomskin layer is part of the three-dimensional object; an energy source forgenerating an energy beam that is configured to transform at least aportion of the at least a fraction of the pre-transformed material to atransformed material as part of the three-dimensional object, whereinthe energy source is disposed adjacent to the material bed; and one ormore controllers operatively coupled to the material bed, the layerdispensing mechanism and the energy source, which one or morecontrollers are individually or collectively programmed to direct theenergy beam to: (I) transform the at least a portion of thepre-transformed material to a first portion of transformed material,which first portion has a first lateral cross section; and (II) increasea temperature of a second portion that (a) is part of the bottom skinlayer and (b) has a second lateral cross section that overlaps the firstlateral cross section, to at least a target temperature value that is atleast one of (i) above the solidus temperature and below the liquidustemperature of the material of the bottom skin layer, and (ii) at atemperature at which the material of the bottom skin layer in the secondportion plastically yields.

The pre-transformed material may comprise a particulate material formedof at least one member selected from the group consisting of elementalmetal, metal alloy, ceramic, an allotrope of elemental carbon, polymer,and resin. The pre-transformed material may comprise a particulatematerial formed of at least one member selected from the groupconsisting of elemental metal, metal alloy, ceramic, and an allotrope ofelemental carbon. The increase in (II) can comprise using feedback orfeed-forward control. The one or more controllers can be individually orcollectively programmed to direct the energy beam to increase thetemperature of the second portion using feedback or feed-forwardcontrol. The increase in (II) can comprise using closed loop or openloop (e.g., temperature) control. The one or more controllers areindividually or collectively programmed to direct the energy beam toincrease the temperature of the second portion using closed loop or openloop control. The increase in (II) can comprise using a graphicalprocessing unit (GPU), system-on-chip (SOC), application specificintegrated circuit (ASIC), application specific instruction-setprocessor (ASIPs), programmable logic device (PLD), or fieldprogrammable gate array (FPGA). The one or more controllers can beindividually or collectively programmed to direct the energy beam toincrease the temperature of the second portion using a graphicalprocessing unit (GPU), system-on-chip (SOC), application specificintegrated circuit (ASIC), application specific instruction-setprocessor (ASIPs), programmable logic device (PLD), or fieldprogrammable gate array (FPGA). The material bed may be formed at leastby dispensing a (e.g., planar) layer of the pre-transformed materialgenerated by removing an excess of pre-transformed material from theexposed surface of the material bed using a gas flow and cyclonicallyseparating the pre-transformed material from the gas flow. The (e.g.,first or second portion of the) transformed material can comprise a meltpool. The system may further comprise repeating at least (B) after (C).

In another aspect, a system for printing a three-dimensional objectcomprises: a platform and a bottom skin layer of hardened materialdisposed above the platform; a material dispenser configured to dispensea pre-transformed material towards a target surface though an opening ofthe material dispenser, wherein the material dispenser is disposedadjacent to the target surface; an energy source configured to generatean energy beam that transforms at least a portion of the pre-transformedmaterial at or adjacent to the target surface, wherein the energy sourceis disposed adjacent to the target surface; and one or more controllersoperatively coupled to the material bed and the energy source, whereinthe one or more controllers are individually or collectively programmedto: (I) direct the energy beam to transform the at least a portion ofthe pre-transformed material at or adjacent to the target surface to atransformed material disposed above the bottom skin layer, and (II)control at least one characteristics of the energy beam such that atemperature of the three-dimensional object at the bottom skin layerbelow the portion is at least one of (i) above the solidus temperatureand below the liquidus temperature of the bottom skin layer material,and (ii) at temperature at which a material in the bottom skin layerplastically yields.

Above in (I) can be directly above such that the transformed materialcontacts the bottom skin layer. The controller may further directrepeating operation (I). The one or more controllers are individually orcollectively programmed to repeat (I) subsequent to (II). Above can bedirectly above such that the bottom skin layer contacts the platform.Above can be indirectly above such that the bottom skin layer does notconnect and/or contact the platform. The bottom skin layer can beseparated from the platform by the pre-transformed material. The bottomskin layer can be separated from the platform by a layer of thepre-transformed material. The bottom skin layer may float anchorlesslyabove the platform. The bottom skin layer can comprise one or moreauxiliary supports. The one or more auxiliary supports can be anchoredto the platform. The one or more auxiliary supports may floatanchorlessly above the platform. The dispenses in operation (b) cancomprise streams. The control can comprise closed loop or open loopcontrol. The increase can comprise using feedback or feed-forwardcontrol. The control can comprise using a simulation. The simulation cancomprise a temperature or mechanical simulation of the 3D printing. Thesimulation may comprise thermo-mechanical simulation. The simulation cancomprise a material property of the requested 3D-object. Thethermo-mechanical simulation can comprise elastic or plastic simulation.The control can comprise using a graphical processing unit (GPU),system-on-chip (SOC), application specific integrated circuit (ASIC),application specific instruction-set processor (ASIPs), programmablelogic device (PLD), or field programmable gate array (FPGA). The methodmay Further comprise a cyclonic separator to separate any excess ofpre-transformed material that did not transform to form thethree-dimensional object. The transformed material can comprise a meltpool. The system may further comprise repeating at least operation (b)after operation (c). Below the portion may be along a directionperpendicularly towards the platform. The bottom skin layer may be belowthe portion along a direction perpendicular to the platform. The atleast one characteristics can comprise power density, cross sectionalarea, trajectory, speed, focus, energy profile, dwell time, intermissiontime, or fluence of the energy beam.

In another aspect, a system for printing a three-dimensional objectcomprises: a container configured to support a material bed comprisingan exposed surface, a pre-transformed material, and a bottom skin layerof hardened material, wherein at least a fraction of the pre-transformedmaterial is disposed above the bottom skin layer, wherein the bottomskin layer is part of the three-dimensional object; an energy sourceconfigured to generate an energy beam that transforms at least a portionof the at least a fraction of the pre-transformed material to atransformed material as part of the three-dimensional object, whereinthe energy source is disposed adjacent to the material bed; and one ormore controllers operatively coupled to the material bed and the energysource, which one or more controllers are individually or collectivelyprogrammed to: (I) transform the at least a portion of thepre-transformed material to a first portion of transformed material, and(II) control at least one characteristics of the energy beam such that atemperature of the three-dimensional object at the bottom skin layerbelow the first portion is at least one of (i) above the solidustemperature and below the liquidus temperature of the bottom skin layermaterial, and (ii) at temperature at which a material in the bottom skinlayer plastically yields.

Below the first portion can be along a direction perpendicular to theaverage plane of the bottom skin layer. Below the first portion may betowards the bottom skin layer. Control can comprise altering at leastone characteristics of the energy beam. The at least one characteristicsof the energy beam can comprise power density, cross sectional area,trajectory, speed, focus, energy profile, dwell time, intermission time,or fluence of the energy beam. Disposed in operation (a) can comprisedispensing a layer of the pre-transformed material by removing an excessof pre-transformed material from the exposed surface of the material bedusing a gas flow and cyclonically separating the pre-transformedmaterial from the gas flow. During the 3D printing, the bottom skinlayer can be the first formed layer of (i) the three-dimensional object,(ii) a hanging structure of the three-dimensional object, or (iii) acavity ceiling of the three-dimensional object. The bottom skin layermay have a sphere of radius XY on a bottom surface of the bottom skinlayer, wherein an acute angle between the straight line XY and thedirection normal to the average layering plane of the bottom skin layeris in the range from about 45 degrees to about 90 degrees. During the 3Dprinting the first formed layer of the three-dimensional object maycomprise auxiliary support that are spaced apart by 2 millimeters ormore. The hanging structure of the three-dimensional object may have atleast one side that is not connected to the three-dimensional object orto the platform. The hanging structure may comprise auxiliary supportsthat are spaced apart by 2 millimeters or more. The cavity ceiling ofthe three-dimensional object may have at least one side that is notconnected to the three-dimensional object or to the platform. Thehanging structure may comprise auxiliary supports that are spaced apartby 2 millimeters or more.

The energy source can comprise an electromagnetic beam or a particlebeam. The electromagnetic beam can comprise a laser. The particle beamcan comprise an electron beam. The pre-transformed material can comprisea solid, semi solid, or liquid material. The pre-transformed materialcan comprise a particulate material. The particulate material cancomprise powder or vesicles. The powder can comprise solid material. Thepre-transformed material may comprise a particulate material formed ofat least one member selected from the group consisting of elementalmetal, metal alloy, ceramic, an allotrope of elemental carbon, polymer,and resin. The pre-transformed material may comprise a particulatematerial formed of at least one member selected from the groupconsisting of elemental metal, metal alloy, ceramic, and an allotrope ofelemental carbon. The pre-transformed material can comprise a polymer orresin. The pre-transformed material and the bottom skin layer cancomprise (e.g., substantially) the same material. The pre-transformedmaterial and the bottom skin layer can comprise different materials. Thethree-dimensional object can comprise functionally graded materials.

In another aspect, a method for printing a three-dimensional objectcomprises: (a) providing a material bed comprising an exposed surfaceand a pre-transformed material; (b) planarizing the exposed surface bydisplacing with a first force, the pre-transformed material from theexposed surface into an internal compartment of a material remover; (c)removing the pre-transformed material from the internal compartment witha second force; and (d) using an energy beam to irradiate at least aportion of the exposed surface to transform the pre-transformed materialat the at least the portion of the exposed surface into a transformedmaterial, wherein the transformed material is at least a portion of thethree-dimensional object.

Displacing the pre-transformed material can comprise attracting thepre-transformed material. Removing the pre-transformed material cancomprise pushing or attracting the pre-transformed material. The firstforce can be different from the second force in at least one of forcetype, force direction, and force amount. Removing can be after theplanarizing in operation (b). Removing can be after the using inoperation (d). Removing in operation (d) may be contemporaneous with theusing in operation (d). A direction of the first force may besubstantially perpendicular to a direction of the second force. Thesecond force may be directed (e.g., may run) perpendicular to firstforce. The pre-transformed material may accumulate in the internalcompartment of the material remover (e.g., material removal mechanism).Accumulate may be during the removing in operation (c). While removingthe pre-transformed material, the pre-transformed material mayaccumulate in the internal compartment of the material remover.Accumulate can comprise separating the pre-transformed material from agas flow that is formed during the displacing (e.g., attracting)operation. Separating can comprise cyclonically separating. Thedirection of the first force may be substantially perpendicular to thedirection of the second force. The first force may be generated by afirst force source. The second force may be generated by a second forcesource. The first force source may be connected to the internalcompartment though a first opening. The second force source may beconnected to the internal compartment though a second opening. The firstopening may be different than the second opening. The first opening maybe the same as the second opening. At least one of the first opening andthe second opening may comprise a valve. At least one of the first forceand second force may be regulated by the valve. The pre-transformedmaterial that is removed in operation (c) may be treated. Treated maycomprise separated and/or reconditioned. The pre-transformed materialthat is removed in (c) may be recycled (e.g., to be used to form thematerial bed). The method may further comprise, subsequent to operation(b) or contemporaneous with operation (b), recycling the pre-transformedmaterial for use in the material bed. The treatment and/or recycling maybe (e.g., continuous) during the 3D printing. The pre-transformedmaterial may be recycled during the 3D printing.

In another aspect, a method for printing a three-dimensional objectcomprises: (a) providing a material bed comprising an exposed surfaceand a pre-transformed material; (b) planarizing the exposed surface bydisplacing the pre-transformed material from the exposed surface into aninternal compartment of a material remover, which pre-transformedmaterial accumulates within the internal compartment while planarizingthe exposed surface; and (c) using an energy beam to irradiate at leasta portion of the exposed surface to transform the pre-transformedmaterial at the at least the portion of the exposed surface into atransformed material, wherein the transformed material is at least aportion of the three-dimensional object.

The accumulation of pre-transformed material can comprise separating thepre-transformed material from a gas flow that is formed whiledisplacing. The pre-transformed material may accumulate at least in partby separating the pre-transformed material from a gas flow that isformed while displacing the pre-transformed material from the exposedsurface. The pre-transformed material may be cyclonically separated fromthe gas flow. Displacing the pre-transformed material may compriseattracting the pre-transformed material (e.g., using electrostaticforce, magnetic force, or gas flow). The gas flow may be pressurized gasor vacuum. For example, the gas flow may be due to a vacuum source. Thematerial remover may be disconnected from (e.g., separated from, and/ordoes not contact) the exposed surface at least while planarizing theexposed surface. The material remover can be separated from the exposedsurface by a gaseous gap (e.g., any gap disclosed herein). Thedisplacing can comprise a gas flow. The pre-transformed material mayseparate from the gas flow in the internal compartment (e.g., as itaccumulates within the internal compartment). While planarizing theexposed surface can comprise while planarizing the exposed surface ofthe material bed one or more times (e.g., one or more planarizationruns). For example, while planarizing the exposed surface can comprisewhile planarizing one exposed surface of the material bed (e.g., asingle planarization run of the material remover). The separation of thepre-transformed material from the gas flow can comprise cyclonicseparation.

In another aspect, a system for printing a three-dimensional objectcomprises: container configured to support a material bed comprising anexposed surface and a pre-transformed material; a first force sourceconfigured to generate a first force that displaces the pre-transformedmaterial in a direction away from the gravitational center, wherein thefirst force source is disposed adjacent to the material bed; a secondforce source configured to generate a second force that maneuvers thepre-transformed material, wherein the second force source is disposedadjacent to the material bed; a material remover comprising an internalcompartment, which material remover is configured to displace (e.g.,facilitates displacing) a portion of the exposed surface to planarizethe exposed surface of the material bed by using the first force,wherein the material remover is operatively coupled to the first forcesource and to the second force source, wherein the material remover isdisposed adjacent to the material bed; an energy source configured togenerate an energy beam that transforms at least a portion of theexposed surface to a transformed material as part of thethree-dimensional object, wherein the energy source is disposed adjacentto the material bed; and one or more controllers operatively coupled tothe material bed, the material remover, the first force source, thesecond force source, and the energy source, which one or morecontrollers direct (i) the material remover to planarize the exposedsurface by displacing at least the pre-transformed material from theexposed surface to the internal compartment by using the first force,and (ii) the material remover to maneuver the pre-transformed materialaway from the internal compartment by using the second force, and (iii)the energy source to transform at least a portion of the pre-transformedmaterial with the energy beam to a transformed material as part of thethree-dimensional object.

Planarize in operation (i) can comprise additionally displacing a debrisfrom the exposed surface to the internal compartment by using the firstforce. The debris can comprise a transformed material that is not partof the three-dimensional object. Away from the internal compartment cancomprise away from the material remover. The first force may bedifferent from the second force. The first force can be different fromthe second force in a force type or a force amount. For example, thefirst force may be vacuum and the second force may be compressed air.The first force source can be different from the second force source.Maneuvering can be in a direction that is (e.g., substantially)perpendicular to the attracting. The first force source can compriseelectronic force, magnetic force, pressurized gas, or vacuum. The secondforce source can comprise electronic force, magnetic force, pressurizedgas, or vacuum. Displacing can comprise attracting. Maneuver cancomprise repel or push. Operation (ii) may occur after planarizing thematerial bed in operation (i) to form a planar exposed surface of thematerial bed.

In some embodiments, the one or more controllers are a plurality ofcontrollers, and wherein at least two operations (e.g., of thecontroller, the apparatus, the method, or the system) are control withthe same controller. For example, the one or more controllers may be aplurality of controllers, and wherein at least two of operations (i),(ii), and (iii) are control with the same controller. In someembodiments, the one or more controllers are a plurality of controllers,wherein at least two operations (e.g., of the controller, the apparatus,the method, or the system) are controlled by different controllers(e.g., that are operatively coupled). For example, the one or morecontrollers may be a plurality of controllers, and wherein at least twoof operations (i), (ii), and (iii) are control with differentcontrollers (e.g., that are operatively coupled). In some embodiments,the one or more controllers directs at least one of a plurality ofoperations (e.g., of the controller, the apparatus, the method, or thesystem) in real time during the 3D printing. In some embodiments, theone or more controllers directs at least one of a plurality ofoperations (e.g., of the controller, the apparatus, the method, or thesystem) in real time during the 3D printing. For example, the one ormore controllers directs at least one of operations (i), (ii), and (iii)in real time during the 3D printing.

In another aspect, a system for printing a three-dimensional objectcomprises: a container configured to support a material bed comprisingan exposed surface and a pre-transformed material; a material removercomprising an internal compartment, which material remover is configuredto displace a portion of the pre-transformed material from the exposedsurface to planarize the exposed surface of the material bed, whereinthe material remover is disposed adjacent to the material bed; an energysource that is configured to generate an energy beam that transforms atleast a portion of the exposed surface to a transformed material as partof the three-dimensional object, wherein the energy source is disposedadjacent to the material bed; and one or more controllers operativelycoupled to the material bed, the material remover, and the energysource, which one or more controllers direct (i) the material remover toplanarize the exposed surface by displacing at least the pre-transformedmaterial from the exposed surface to accumulate in the internalcompartment, and (ii) the energy source to transform at least a portionof the pre-transformed material with the energy beam to a transformedmaterial as part of the three-dimensional object.

Accumulate may be during the planarize to form a planar exposed surfaceof the material bed. Planarize in (i) can comprise additionallydisplacing a debris from the exposed surface to the internal compartmentby using the first force. The debris can comprise a transformed materialthat is not part of the three-dimensional object.

In another aspect, a method for 3D printing comprises: (a) providing amaterial bed within an enclosure; and (b) irradiating a tiling energyflux onto an exposed surface of the material bed in a first position fora first time-period to form a first heated tile, which tiling energyflux is substantially uniform within a footprint of the first heatedtile, wherein the tiling energy flux is substantially stationary withinthe first time-period, and wherein at least one characteristics of thetiling energy flux is determined using a measurement within (e.g., of)the first heated tile.

In another aspect, a method for printing a three-dimensional objectcomprises: (a) providing a material bed comprising an exposed surfaceand a pre-transformed material; (b) planarizing the exposed surface byattracting the pre-transformed material from the exposed surface into aninternal compartment of a material remover though a nozzle of thematerial remover, which nozzle comprises an adjustable volume; and (c)using an energy beam to transform at least a portion of the exposedsurface to a transformed material, wherein the transformed material asat least a portion of the three-dimensional object.

Planarizing may be in the absence of contact between the materialremover and the exposed surface of the material bed. The pre-transformedmaterial may accumulate in the internal compartment. Accumulate cancomprise separating the pre-transformed material from a gas flow that isformed during the attracting. The separating can be cyclonicallyseparating. Attracting can comprise using an electrostatic force,magnetic force, or gas flow. The pre-transformed material may beattracted using an electrostatic force, magnetic force, or gas flow. Thegas flow can comprise vacuum or compressed gas. The adjustable volumecan be the internal volume of the nozzle. The nozzle can comprise atleast one adjustable part. The part can be a mechanical part. The nozzlecan comprise at least two, three or four adjustable parts. The nozzlecan comprise a Venturi nozzle. The adjustable volume of the nozzle canbe asymmetric. The method may further comprise adjusting the nozzle toregulate the volume (e.g., area and/or depth) from which thepre-transformed material is attracted from the material bed into thenozzle. The method may further comprise adjusting the nozzle to regulatea rate at which the pre-transformed material is attracted from thematerial bed into the nozzle. The method may further comprise adjustingthe nozzle to regulate the fidelity at which the exposed surface isplanarized.

In another aspect, a method for printing a three-dimensional objectcomprises: (a) providing a material bed comprising an exposed surfaceand a pre-transformed material; (b) planarizing the exposed surface byattracting the pre-transformed material from the exposed surface thougha nozzle of a material remover, which attracting comprises using anattractive force that is substantially equal along a horizontalcross-section of the nozzle, which nozzle spans at least a portion of awidth of the material bed that is perpendicular to the direction ofmovement of the material remover; and (c) using an energy beam totransform the at least the portion of the width of the material bed intoa transformed material, wherein the transformed material is at least aportion of the three-dimensional object.

The at least a portion may be greater than 50%, 80%, 90%, or 100% of thewidth of the material bed. For example, the at least the portion of thewidth of the material bed may be greater than 50% of the width of thematerial bed. The pre-transformed material that is attracted though thenozzle may accumulate in an internal compartment of the materialremover. Accumulate can comprise separate the pre-transformed materialfrom a gas flow that may be formed during the attracting. Thepre-transformed material may accumulate in the internal compartment atleast in part by separating the pre-transformed material from a gas flowthat is formed upon attracting the pre-transformed material from theexposed surface though a nozzle of a material remover. The separationmay be cyclonic separation. In some embodiments, a vertical crosssectional area of the internal compartment is greater by at least aboutthree times, ten times, thirty times, or fifty times a horizontal crosssectional area of the opening of the nozzle. For example, a verticalcross sectional area of the internal compartment is greater by at leastthree times the horizontal cross sectional area of the nozzle opening.The method may further comprise controlling the attractive force toregulate the volume from which the pre-transformed material is attractedfrom the material bed into the nozzle. The method may further comprisecontrolling the attractive force to regulate the rate at which thepre-transformed material is attracted from the material bed into thenozzle. The method may further comprise controlling the attractive forceto regulate the fidelity at which the material remover planarizes theexposed surface. The method may further comprise controlling thetranslational speed of the material remover across the material bed toregulate the fidelity at which the material remover planarizes theexposed surface.

In another aspect, A method for printing a three-dimensional object,comprising: (a) providing a material bed comprising an exposed surfaceand a pre-transformed material; (b) planarizing the exposed surface bydisplacing (e.g., attracting) the pre-transformed material from theexposed surface into an internal compartment of a material remover,which internal compartment has a narrowing horizontal cross-section; and(c) using an energy beam to irradiate at least a portion of the exposedsurface to transform the pre-transformed material at the at least theportion of the exposed surface into a transformed material, wherein thetransformed material is at least a portion of the three-dimensionalobject.

The narrowing horizontal cross section may have a long axis that is(e.g., substantially) perpendicular to a direction of movement of thematerial remover (e.g., along the exposed surface). The pre-transformedmaterial may accumulate in the internal compartment of the materialremover. The material remover may comprise an opening that is directedtowards the exposed surface of the material bed (e.g., and toward aplatform on which the material bed is disposed). The opening may be theopening through which the pre-transformed material enters the materialremoval (e.g., and into the internal compartment thereof). Accumulatecan comprise separating the pre-transformed material from a gas flowthat may be formed during the attracting. Separating may comprisecyclonically separating. The material bed can be disposed above aplatform. The narrowing horizontal cross-section may be (e.g.,substantially) parallel to the platform. The internal compartment maycomprise a narrowing (e.g., conical) shape (e.g., having its long axisparallel to the platform). The attracting may be from a position in thelarger cross sectional vertical face of the cone (e.g., base of thecone). For example, the attracting may be from a position in the largercircular cross section of the cone (e.g., base of the cone). Thenarrowing horizontal cross section may have an axis that is (e.g.,substantially) perpendicular to the direction of movement. Thepre-transformed material is displaced using a force that is distributed(e.g., substantially) homogenously along the horizontal cross section(e.g., wherein substantially is relative to the operation of thematerial remover, for example, relative to the resulting planarity ofthe exposed surface). The planarizing may form a (e.g., substantially)planar exposed surface of the material bed within a height error rangeof at most about 500 micrometers, 300 micrometers, 200 micrometers, 150micrometers, 100 micrometers, 50 micrometers, 30 micrometers, or 20micrometers. For example, the planarizing may form a (e.g.,substantially) planar exposed surface of the material bed within aheight error range of at most about 200 micrometers.

In another aspect, a system for printing a three-dimensional objectcomprises: a container configured to support a material bed comprisingan exposed surface and a pre-transformed material; a material removercomprising a nozzle through which pre-transformed material is displaced(e.g., attracted) away from the exposed surface, which nozzle comprisesan adjustable volume, wherein the material remover is disposed adjacentto the material bed; an energy source configured to project an energybeam that transforms a portion of the pre-transformed material into atransformed material as part of the three-dimensional object, whereinthe energy source is disposed adjacent to the material bed; and one ormore controllers operatively coupled to the material bed, the materialremover, and the energy source, which one or more controllers direct (i)the material remover to adjust the volume of the nozzle, (ii) thematerial remover to planarize the exposed surface, and (iii) the energysource to transform at least a portion of the pre-transformed materialwith the energy beam to a transformed material as part of thethree-dimensional object.

The one or more controllers may be a plurality of controllers. At leasttwo of operations (i), (ii), and (iii) may be controlled by the samecontroller. At least two of operations (i), (ii), and (iii) may becontrolled by different controllers (e.g., that are operativelycoupled). The one or more controllers may direct at least one ofoperations (i), (ii), and (iii) in real time during the 3D printing.Adjust may be during the 3D printing. Adjust may be before the 3Dprinting.

In another aspect, a system for printing a three-dimensional objectcomprises: a container configured to support a material bed comprisingan exposed surface and a pre-transformed material; a force source thatis configured to generate an attractive force that attracts thepre-transformed material, wherein the force source is disposed adjacentto the material bed; a material remover comprising a nozzle that spansat least a portion of the width of the material bed that isperpendicular to the direction of movement of the material remover,which material remover planarizes the exposed surface by attracting aportion of the pre-transformed material; an energy source that isconfigured to generate an energy beam that transforms at least a portionof the exposed surface to a transformed material as part of thethree-dimensional object, wherein the energy source is disposed adjacentto the material bed; and one or more controllers operatively coupled tothe material bed, the material remover, the force source, and the energysource, which one or more controllers direct (i) the material remover toplanarize the exposed surface by attracting the pre-transformed materialfrom the exposed surface though the nozzle, which attracting comprisesusing an attractive force that is substantially equal along thehorizontal cross section of the nozzle entrance opening through whichthe pre-transformed material enters the material-removal mechanism, and(ii) the energy source to transform at least a portion of thepre-transformed material with the energy beam to a transformed materialas part of the three-dimensional object.

The one or more controllers may be one controller. The one or morecontrollers may be a plurality of controllers. Each of operations (i),and (ii), may be controlled by different controllers (e.g., that areoperatively coupled).

In another aspect, a system for printing a three-dimensional objectcomprises: a container configured to enclose a material bed comprisingan exposed surface and a pre-transformed material; a material removercomprising an internal compartment having a narrowing horizontal crosssection, which material remover is configured to attract a portion ofthe pre-transformed material from the exposed surface to planarize theexposed surface of the material bed, wherein the material remover isdisposed adjacent to the material bed; an energy source configured togenerate an energy beam that transforms at least a portion of theexposed surface to a transformed material as part of thethree-dimensional object, wherein the energy source is disposed adjacentto the material bed; and one or more controllers operatively coupled tothe material bed, the material remover, and the energy source, which oneor more controllers direct (i) the material remover to planarize theexposed surface by attracting the pre-transformed material from theexposed surface though the nozzle, which attracting comprises using anattractive force that is substantially equal along the horizontal crosssection of the nozzle, and (ii) the energy source to transform at leasta portion of the pre-transformed material with the energy beam to atransformed material as part of the three-dimensional object.

The one or more controllers may be one controller. The one or morecontrollers may be a plurality of controllers. Each of operations (i),and (ii), may be controlled by different controllers (e.g. that areoperatively coupled).

In another aspect, a method for printing a three-dimensional objectcomprises: providing a material bed comprising a pre-transformedmaterial above a platform; generating a layer of transformed material aspart of the three-dimensional object, which generating comprisesirradiating a first portion of the material bed with a first energy beamto transform the pre-transformed material in the first portion into afirst transformed material as part of the three-dimensional object,which first energy beam travels along a first trajectory; andcontrolling at least one of (i) a temperature and (ii) a shape of thefirst transformed material, wherein said controlling is in real time(e.g., during formation of the first transformed material).

The first transformed material can comprise a melt pool. The method mayfurther comprise irradiating a second portion of the material bed with asecond energy beam to transform the pre-transformed material into asecond transformed material as part of the three-dimensional object. Thesecond energy beam may travel along a second trajectory that can bedifferent from the first trajectory. The second energy beam can bedifferent from the first energy beam by at least one characteristics.The at least one characteristics can comprise power density, crosssectional area, trajectory, speed, focus, energy profile, dwell time,intermission time, or fluence of the energy beam. Controlling mayfurther comprise controlling at least one of (i) a temperature and (ii)a shape, of the first transformed material. The control can be in realtime (e.g., during formation of the second transformed material). Thesecond transformed material can be a melt pool. The providing maycomprise dispensing a layer of the pre-transformed material by removingan excess of pre-transformed material from the exposed surface of thematerial bed using a gas flow (e.g., and cyclonically separating thepre-transformed material from the gas flow).

In another aspect, a system for printing a three-dimensional objectcomprises: a container configured to enclose material bed comprising anexposed surface and a pre-transformed material; a first energy sourceconfigured to generate a first energy beam that transforms at least aportion of the material bed to a transformed material as part of thethree-dimensional object, wherein the first energy source is disposedadjacent to the material bed; and one or more controllers operativelycoupled to the material bed, and the first energy source, which one ormore controllers (e.g., individually or collectively) (I) direct thefirst energy beam to generate a first transformed material from a firstportion of the material bed, which first energy beam travels along afirst trajectory, and (II) control at least one of (i) a temperature and(ii) a shape, of the first transformed material, which control is inreal time (e.g., during formation of the first transformed material toform the three-dimensional object).

The first transformed material can comprise a first melt pool. Thesystem may further comprise a second energy source generating a secondenergy beam that transforms at least a portion of the material bed to atransformed material as part of the three-dimensional object. The secondenergy source can be disposed adjacent to the material bed. The one ormore controllers may further be operatively coupled to the second energysource. The one or more controllers may direct the second energy beam togenerate a second transformed material from a second portion of thematerial bed. The second portion of the material bed can be differentfrom the first portion of the material bed. The second energy beam maytravel along a second trajectory. The second trajectory can be differentfrom the first trajectory. The one or more controllers may control atleast one of (i) a temperature and (ii) a shape, of the secondtransformed material. The control can be in real time (e.g., duringformation of the second transformed material to form the 3D object). Thesecond energy beam can be different from the first energy beam by atleast one characteristics. The at least one characteristics can comprisepower density, cross sectional area, trajectory, speed, focus, energyprofile, dwell time, intermission time, or fluence of the energy beam.The second transformed material can comprise a second melt pool (e.g.,that is different from the first melt pool).

In another aspect, a method for 3D printing comprises: (a) providing amaterial bed within an enclosure; and (b) irradiating a tiling energyflux onto an exposed surface of the material bed in a first position fora first time period to form a first heated tile, which tiling energyflux is substantially uniform within a footprint of the first heatedtile, wherein the tiling energy flux is substantially stationary withinthe first time period, and wherein at least one characteristics of thetiling energy flux is determined using a measurement within (e.g., of)the first heated tile.

The at least one characteristics can comprise wavelength, power,amplitude, trajectory, footprint, intensity, energy, fluence, AndrewNumber, hatch spacing, scan speed, or charge. The measurement can be atemperature measurement. The method may further comprise: (c)translating the tiling energy flux to a second position on the exposedsurface of the material bed; and (d) irradiating the tiling energy fluxfor a second time-period to form a second heated tile, wherein thetiling energy flux is substantially stationary within the secondtime-period. The tiling energy flux may be substantially uniform within(e.g., within the area of) the second heated tile. The material bed maycomprise one or more layers of material. The material bed be may be apowder bed. The material bed may comprise particulate material that isselected from the group consisting of an elemental metal, metal alloy,ceramic, and an allotrope of elemental carbon. A shape of the firstheated tile may be (e.g., substantially) identical to a shape of thesecond heated tile. A shape of the first heated tile may be differentfrom a shape of the second heated tile. The first heated tile may borderthe second heated tile. The second heated tile may at least partiallyoverlap the first heated tile. The second heated tile may be separatedfrom the first heated tile by a gap. The irradiating can compriseheating. The heating may substantially exclude transforming. The heatingmay comprise transforming. The method may further comprise transformingat least a fraction of a material within the first heated tile. Themethod may further comprise transforming at least a fraction of amaterial within the second heated tile. Transforming may comprisefusing. Fusing may comprise melting or sintering. The exposed surface ofthe material bed may comprise an exposed surface of a 3D object thatincludes the first position and the second position. The method mayfurther comprise cooling the material bed using a heat sink disposedabove the exposed surface of the material bed. The cooling may bebefore, during, and/or after step (b). The cooling may be before,during, and/or after step (c). The energy flux may be substantially off(e.g., shut down) between the first position and the second position.The energy flux may be substantially off at least when translatingbetween the first position and the second position. The method mayfurther comprise irradiating at least a portion of the exposed surfaceof the material bed using a scanning energy beam that is different fromthe tiling energy flux. The at least a portion of the exposed surfacemay be disposed within the exposed surface of a 3D object (e.g.,embedded within the material bed). The velocity (e.g., speed) of thescanning energy beam can be at least 50 mm/sec. The exposure time (e.g.,dwell time) of the tiling energy beam may be at least one millisecond.The power per unit area (e.g., power density) of the tiling energy beammay be at most 1000 Watt per millimeter squared. The power per unit areaof the tiling energy beam may be at most 10000 Watt per millimetersquared. The fundamental length scale (abbreviated herein as “FLS”) of across section of the tiling energy beam may be at least 0.3 millimeter.The FLS (e.g., diameter) of a cross section of the scanning energy beamis at most 250 micrometers. FLS may be a diameter, spherical equivalentdiameter, diameter of a bounding circle, or the largest of: height,width, and length. The method may further comprise controlling a rate atwhich the first heated tile cools down. The controlling can compriseimaging the first heated tile. The imaging can comprise analyzing aspectrum. The imaging can comprise image processing. The controlling cancomprise sensing the temperature of the first heated tile. The sensingcan comprise imaging. The sensing can comprise analyzing a spectrum. Thecontrolling can comprise using feedback control. The controlling cancomprise using open loop control.

In another aspect, an apparatus for 3D printing comprises: (a) anenclosure comprising a material bed; and (b) a tiling energy source thatgenerates a tiling energy flux that irradiates an exposed surface of thematerial bed to form a heated tile, which tiling energy flux issubstantially uniform within the first heated tile; and (c) a controlleroperatively coupled to the enclosure and to the tiling energy source anddirects the tiling energy beam to irradiate a first position of theexposed surface for a first time-period to form a first heated tile,wherein the tiling energy flux is substantially stationary within thefirst time-period, wherein at least one characteristics of the tilingenergy flux is determined using a measurement of the first heated tile.

In another aspect, a method for 3D printing comprises: (a) providing amaterial bed within an enclosure; (b) irradiating a tiling energy fluxonto an exposed surface of the material bed in a first position for afirst time-period to form a first heated tile, wherein the irradiatingcomprises altering the power density of the tiling energy flux duringthe first time-period, and wherein the spatial distribution of the powerdensity is substantially uniform within a footprint of the tile (e.g.,on the exposed surface).

The irradiating may be related to a temperature measurement within(e.g., of) the first heated tile. The method can further comprisetranslating the tiling energy flux to a second position on the exposedsurface of the material bed; and irradiating the tiling energy flux fora second time-period to form a second heated tile with the tiling energyflux, which tiling energy flux has a power density during the secondtime-period that is substantially uniform within an area of the secondheated tile. The altering can comprise increasing the power densityfollowed by decreasing the power density. In some embodiments, at leastone of the increasing and decreasing is controlled. The tiling energyflux can be substantially stationary within the first time-period. Atleast one characteristics of the tiling energy flux may be determinedusing a measurement of the first heated tile.

In another aspect, an apparatus for 3D printing comprises: (a) anenclosure comprising a material bed; and (b) a tiling energy source thatgenerates a tiling energy flux that irradiates an exposed surface of thematerial bed for a first time-period to form a heated tile; and (c) acontroller operatively coupled to the enclosure and to the tiling energysource and directs the tiling energy beam to irradiate a first positionof the exposed surface for a first time-period to form a first heatedtile, wherein the irradiate comprises alter the power density of thetiling energy flux during the first time-period, and wherein the spatialdistribution of the power density is substantially uniform within afootprint of the tile (e.g., on the exposed surface).

In another aspect, a method for 3D printing comprises: (a) providing amaterial bed within an enclosure; (b) irradiating a tiling energy fluxto portion of an exposed surface of the material bed in a first positionfor a first time-period to form a first heated tile, wherein a powerdensity of the tiling energy flux during the first time-period issubstantially uniform within an area of the first heated tile on theexposed surface of the material bed, which forming comprises: (i)increasing a power density of the tiling energy flux monotonously acrossan area of the first heated tile up to a power density peak; and (ii)decreasing the power density of the tiling energy flux monotonouslyacross the area of the first heated tile, wherein the time at which thepower density peak is reached for two points within the area of thefirst heated tile is substantially simultaneous.

The area can be a cross section of the tile in the exposed surface ofthe material bed. The at least one of the increasing and the decreasingmay be related to a temperature measurement within the first heatedtile. Within the first heated tile may comprise one or more positionswithin the first heated tile. Within the first tile may be of the firstheated tile. The method can further comprise translating the tilingenergy flux to a second position on the exposed surface of the materialbed; and irradiating the tiling energy flux for a second time-period toform a second heated tile with the tiling energy flux, which tilingenergy flux has a power density during the second time-period that issubstantially uniform within an area of the second heated tile.

In another aspect, an apparatus for 3D printing comprises: (a) anenclosure comprising a material bed; and (b) a tiling energy source thatgenerates a tiling energy flux that irradiates an exposed surface of thematerial bed for a first time-period to form a heated tile, wherein apower density of the tiling energy flux during the first time-period issubstantially uniform within an area of a first heated tile on anexposed surface of the material bed; and (c) a controller operativelycoupled to the enclosure and to the tiling energy source and directs thetiling energy beam to irradiate a first position in the exposed surfaceof the material be for a first time-period to form the heated tile,which form comprises: (i) increase a power density of the tiling energyflux monotonously across an area of the first heated tile up to a powerdensity peak; and (ii) decrease the power density of the tiling energyflux monotonously across the area of the first heated tile, wherein thetime at which the power density peak is reached for two points withinthe area of the first heated tile is substantially simultaneous.

In another aspect, a method for 3D printing comprises: (a) providing amaterial bed within an enclosure; (b) transforming at least a portion ofthe material bed to form a transformed material by forming one or moresuccessive melt pools, which transformed material subsequently hardensto form a hardened material as at least a portion of the 3D object; and(c) controlling the one or more melt-pools in real-time.

The transforming may be related to a temperature measurement within(e.g., at various position within, or of) the first heated tile.Controlling the one or more successive melt-pools can comprisecontrolling the volume of the one or more successive melt-pools.Controlling the one or more successive melt-pools can comprisecontrolling the average fundamental length scale of the one or moresuccessive melt-pools. Controlling the one or more successive melt-poolscan comprise controlling the microstructure of the one or moresuccessive melt-pools. Controlling the one or more successive melt-poolscan comprise controlling the cooling rate of the one or more successivemelt-pools. Controlling the one or more successive melt-pools cancomprise controlling the heating rate of the one or more successivemelt-pools. Controlling the one or more successive melt-pools cancomprise controlling the temperature variation within the one or moresuccessive melt-pools. Controlling the one or more successive melt-poolscan comprise controlling the overall shape of the one or more successivemelt-pools. Controlling the one or more successive melt-pools cancomprise controlling the overall shape of a cross section of the one ormore successive melt-pools. The cross section can comprise a verticalcross section. The cross section can comprise a horizontal crosssection. Controlling can comprise sensing the temperature of the one ormore successive melt-pools. Sensing can comprise imaging (e.g., using acamera). Controlling can comprise evaluating the volume of the melt poolbased on the sensing. Controlling can comprise regulating by acontroller.

In another aspect, a method for generating a three-dimensional object bytiling comprises: a) depositing a layer of pre-transformed material toform a material bed; b) providing a first energy beam to a first portionof the layer of pre-transformed material at a first location totransform the pre-transformed material at the first portion to form afirst tile of transformed material; c) moving the first energy beam to asecond location at the layer of pre-transformed material, wherein themoving is at a speed of at most about 500 millimeters per second; and d)providing the first energy beam to a second portion of the layer ofpre-transformed material at the second location to transform thepre-transformed material at the second portion to form a second tile oftransformed material; wherein the first tile of transformed material andsecond tile of transformed material harden to form at least a portion ofthe three-dimensional object.

The moving can be at a speed of at most about 200 millimeters persecond. The moving can be at a speed of at most about 100 millimetersper second. The moving can be at a speed of at most about 50 millimetersper second. The moving can be at a speed of at most about 30 millimetersper second. The first energy beam may have a power density of at mostabout 5000 watts per millimeter square. The first energy beam may have apower density of at most about 3000 watts per millimeter square. Thefirst energy beam may have a power density of at most about 1500 wattsper millimeter square. The first energy beam may have a diameter of atleast about 200 micrometers. The first energy beam may have a diameterof at least about 300 micrometers. The first energy beam may have adiameter of at least about 400 micrometers.

Another aspect of the present disclosure provides a system foreffectuating the methods disclosed herein.

Another aspect of the present disclosure provides an apparatus foreffectuating the methods disclosed herein. The apparatus can be any ofthe system described above that omit the one or more controllers. Theapparatus can be any of the system described above that include (e.g.,only include) the one or more controllers.

Another aspect of the present disclosure provides an apparatuscomprising a controller that directs effectuating one or more steps inthe method disclosed herein, wherein the controller is operativelycoupled to the apparatuses, systems, and/or mechanisms that it controlsto effectuate the method.

Another aspect of the present disclosure provides a computer systemcomprising one or more computer processors and a non-transitorycomputer-readable medium coupled thereto. The non-transitorycomputer-readable medium comprises machine-executable code that, uponexecution by the one or more computer processors, implements any of themethods above or elsewhere herein.

Another aspect of the present disclosure provides an apparatus forprinting one or more 3D objects comprises a controller that isprogrammed to direct a mechanism used in a 3D printing methodology toimplement (e.g., effectuate) any of the method disclosed herein, whereinthe controller is operatively coupled to the mechanism.

Another aspect of the present disclosure provides a computer softwareproduct, comprising a non-transitory computer-readable medium in whichprogram instructions are stored, which instructions, when read by acomputer, cause the computer to direct a mechanism used in the 3Dprinting process to implement (e.g., effectuate) any of the methoddisclosed herein, wherein the non-transitory computer-readable medium isoperatively coupled to the mechanism.

Another aspect of the present disclosure provides a non-transitorycomputer-readable medium comprising machine-executable code that, uponexecution by one or more computer processors, implements any of themethods disclosed herein.

Additional aspects and advantages of the present disclosure will becomereadily apparent to those skilled in this art from the followingdetailed description, wherein only illustrative embodiments of thepresent disclosure are shown and described. As will be realized, thepresent disclosure is capable of other and different embodiments, andits several details are capable of modifications in various obviousrespects, all without departing from the disclosure. Accordingly, thedrawings and description are to be regarded as illustrative in nature,and not as restrictive.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent, or patent application wasspecifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings or figures (also “FIG.” and “FIGS.” herein), ofwhich:

FIG. 1 shows a schematic side view of a 3D printing system andapparatuses.

FIG. 2 illustrates a top view of various apertures;

FIG. 3 illustrates schematic top view of 3D objects;

FIGS. 4A-4E illustrate schematic top view of various 3D objects;

FIGS. 5A-5I illustrate schematic top view of various 3D objects;

FIGS. 6A-6G illustrate schematic top view of various 3D objects;

FIG. 7 illustrates a path;

FIG. 8 illustrates various paths;

FIG. 9 schematically illustrates an optical system;

FIGS. 10A-10C illustrate various vertical cross sections of a materialbed;

FIGS. 11A-11B illustrate schematic vertical cross sections of 3Dobjects;

FIGS. 12A-12C schematically illustrate various top views of portions of3D objects;

FIG. 13 schematically illustrates a side view of a layer dispensingmechanism and various components thereof;

FIG. 14 schematically illustrates vertical cross sectional view of amaterial removal mechanism;

FIG. 15 schematically illustrates vertical cross sectional view ofvarious nozzles;

FIG. 16 shows a schematic side view of a 3D printing system andapparatuses;

FIG. 17 shows various vertical cross sectional views of different 3Dobjects;

FIG. 18 shows a horizontal view of a 3D object;

FIG. 19 schematically illustrates a coordinate system;

FIGS. 20A-20C show various 3D objects;

FIGS. 21A-21D show schematic top views of 3D objects

FIG. 22 schematically illustrates a computer control system that isprogrammed or otherwise configured to facilitate the formation of one ormore 3D objects;

FIG. 23 schematically illustrates a flow chart for a control system;

FIG. 24 schematically illustrates spatial intensity profiles of variousenergy beams and/or fluxes;

FIG. 25 shows a schematic side view of a 3D printing system andapparatuses;

FIG. 26 shows a schematic top view of a 3D object;

FIG. 27 shows a schematic example of a 3D plane;

FIGS. 28A-28C show various schematic bottom views of powder removalmechanisms;

FIGS. 29A-29E show various schematic bottom views of powder removalmechanisms;

FIG. 30 shows top views of 3D objects;

FIG. 31 illustrates tiling patterns;

FIG. 32 shows temperature dependence timelines;

FIG. 33 schematically illustrates side view of a material removalmechanism;

FIGS. 34A-34D schematically illustrate side views of layer dispensingmechanisms and various components thereof;

FIGS. 35A-35B schematically illustrate steps in forming a 3D object;

FIG. 36 shows examples of 3D objects;

FIG. 37 schematically illustrates steps in forming a 3D object viewedfrom the top;

FIG. 38 schematic illustrates a side view of a 3D object in a materialbed;

FIGS. 39A-39B show examples of 3D objects;

FIG. 40 schematically illustrates an optical system;

FIG. 41 schematically shows a cross section in portion of a 3D object;

FIG. 42 schematically illustrates side view of a material removalmechanism;

FIGS. 43A-43B show various views of a material removal mechanisms; and

FIGS. 44A-44F show various views of material removal mechanism parts.

The figures and components therein may not be drawn to scale. Variouscomponents of the figures described herein may not be drawn to scale.

DETAILED DESCRIPTION

While various embodiments of the invention have been shown and describedherein, it will be obvious to those skilled in the art that suchembodiments are provided by way of example only. Numerous variations,changes, and substitutions may occur to those skilled in the art withoutdeparting from the invention. It should be understood that variousalternatives to the embodiments of the invention described herein mightbe employed.

Terms such as “a,” “an” and “the” are not intended to refer to only asingular entity, but include the general class of which a specificexample may be used for illustration. The terminology herein is used todescribe specific embodiments of the invention, but their usage does notdelimit the invention. When ranges are mentioned, the ranges are meantto be inclusive, unless otherwise specified. For example, a rangebetween value 1 and value2 is meant to be inclusive and include value 1and value2. The inclusive range will span any value from about value 1to about value2.

The term “adjacent” or “adjacent to,” as used herein, includes ‘nextto’, ‘adjoining’, ‘in contact with,’ and ‘in proximity to.’ In someinstances, adjacent to may be ‘above’ or ‘below.’

The term “between” as used herein is meant to be inclusive unlessotherwise specified. For example, between X and Y is understood hereinto mean from X to Y.

The term “operatively coupled” or “operatively connected” refers to afirst mechanism that is coupled (or connected) to a second mechanism toallow the intended operation of the second and/or first mechanism.

Three-dimensional printing (also “3D printing”) generally refers to aprocess for generating a 3D object. For example, 3D printing may referto sequential addition of material layer or joining of material layers(or parts of material layers) to form a 3D structure, in a controlledmanner. The controlled manner may include automated and/or manualcontrol. In the 3D printing process, the deposited material can betransformed (e.g., fused, sintered, melted, bound, or otherwiseconnected) to subsequently harden and form at least a part of the 3Dobject. Fusing (e.g., sintering or melting) binding, or otherwiseconnecting the material is collectively referred to herein astransforming the material (e.g., transforming the powder material).Fusing the material may include melting or sintering the material.Binding can comprise chemical bonding. Chemical bonding can comprisecovalent bonding. Examples of 3D printing include additive printing(e.g., layer by layer printing, or additive manufacturing). 3D printingmay include layered manufacturing. 3D printing may include rapidprototyping. 3D printing may include solid freeform fabrication. The 3Dprinting may further comprise subtractive printing.

There are many different 3D printing methodologies. For example, 3Dprinting methodologies can comprise extrusion, wire, granular,laminated, light polymerization, or powder bed and inkjet head 3Dprinting. Extrusion 3D printing can comprise robo-casting, fuseddeposition modeling (FDM) or fused filament fabrication (FFF). Wire 3Dprinting can comprise electron beam freeform fabrication (EBF3).Granular 3D printing can comprise direct metal laser sintering (DMLS),electron beam melting (EBM), selective laser melting (SLM), selectiveheat sintering (SHS), or selective laser sintering (SLS). Powder bed andinkjet head 3D printing can comprise plaster-based 3D printing (PP).Laminated 3D printing can comprise laminated object manufacturing (LOM).Light polymerized 3D printing can comprise stereo-lithography (SLA),digital light processing (DLP), or laminated object manufacturing (LOM).3D printing methodologies can comprise Direct Material Deposition (DMD).The Direct Material Deposition may comprise, Laser Metal Deposition(LMD, also known as, Laser deposition welding). 3D printingmethodologies can comprise powder feed, or wire deposition.

In some embodiments, the 3D printing method is an additive method inwhich a first layer is printed, and thereafter a volume of a material isadded to the first layer as separate sequential layer (or partsthereof). In some examples, each additional sequential layer (or partthereof) is added to the previous layer by transforming (e.g., fusing(e.g., melting)) a fraction of the pre-transformed (e.g., powder)material and subsequently hardening the transformed material to form atleast a portion of the 3D object. The hardening can be actively induced(e.g., by cooling) or can occur without intervention (e.g., naturally bytemperature equilibration with the surrounding).

In some embodiments, 3D printing methodologies differ from methodstraditionally used in semiconductor device fabrication (e.g., vapordeposition, etching, annealing, masking, or molecular beam epitaxy). Forexample, 3D printing methodologies can differ from vapor depositionmethods such as chemical vapor deposition, physical vapor deposition, orelectrochemical deposition. In some instances, 3D printing furthercomprises one or more printing methodologies that are traditionally usedin semiconductor device fabrication. For example, 3D printing mayfurther include vapor deposition methods.

The methods, apparatuses, and systems of the present disclosure can beused to form 3D objects for various uses and applications. Such uses andapplications include, without limitation, electronics, components ofelectronics (e.g., casings), machines, parts of machines, tools,implants, prosthetics, fashion items, clothing, shoes, or jewelry. Theimplants may be directed (e.g., integrated) to a hard, a soft tissue, orto a combination of hard and soft tissues. The implants may formadhesion with hard and/or soft tissue. The machines may include a motoror motor part. The machines may include a vehicle. The machines maycomprise aerospace related machines. The machines may comprise airbornemachines. The vehicle may include an airplane, drone, car, train,bicycle, boat, or shuttle (e.g., space shuttle). The machine may includea satellite or a missile. The uses and applications may include 3Dobjects relating to the industries and/or products listed herein.

The present disclosure provides systems, apparatuses, software, and/ormethods for 3D printing of a requested (e.g., desired) 3D object from apre-transformed material (e.g., powder material). The 3D object (orportions thereof) can be pre-ordered, pre-designed, pre-modeled, ordesigned in real time (e.g., during the process of 3D printing). Forexample, the object may be designed as part of the print preparationprocess of the 3D printing. For example, various portion of the objectmay be designed as other parts of that object are being printed. Realtime is during formation of at least one of: 3D object, a layer of the3D object, dwell time of an energy beam along a path, dwell time of anenergy beam along a hatch line, dwell time of an energy beam forming atile, and dwell time of an energy beam forming a melt pool.

Pre-transformed material, as understood herein, is a material before ithas been first transformed (i.e., once transformed) by an energy beamand/or flux during the 3D printing process. The pre-transformed materialmay be a material that was, or was not, transformed prior to its use inthe 3D printing process. The pre-transformed material may be liquid,solid, or semi-solid (e.g., gel). The pre-transformed material may be aparticulate material. The particulate material may be a powder material.The powder material may comprise solid particles of material. Theparticulate material may comprise vesicles (e.g., containing liquid orsemi-solid material). The particulate material may comprise solid orsemi-solid material particles.

The fundamental length scale (e.g., the diameter, spherical equivalentdiameter, diameter of a bounding circle, or the largest of height, widthand length; abbreviated herein as “FLS”) of the printed 3D object can beat least about 50 micrometers (μm), 80 μm, 100 μm, 120 μm, 150 μm, 170μm, 200 μm, 230 μm, 250 μm, 270 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700μm, 800 μm, 1 millimeter (mm), 1.5 mm, 2 mm, 5 mm, 1 centimeter (cm),1.5 cm, 2 cm, 10 cm, 20 cm, 30 cm, 40 cm, 50 cm, 60 cm, 70 cm, 80 cm, 90cm, 1 m, 2 m, 3 m, 4 m, 5 m, 10 m, 50 m, 80 m, or 100 m. The FLS of theprinted 3D object can be at most about 1000 m, 500 m, 100 m, 80 m, 50 m,10 m, 5 m, 4 m, 3 m, 2 m, 1 m, 90 cm, 80 cm, 60 cm, 50 cm, 40 cm, 30 cm,20 cm, 10 cm, or 5 cm. In some cases, the FLS of the printed 3D objectmay be in between any of the afore-mentioned FLSs (e.g., from about 50μm to about 1000 m, from about 120 μm to about 1000 m, from about 120 μmto about 10 m, from about 200 μm to about 1 m, or from about 150 μm toabout 10 m).

In some examples, the 3D object is a large 3D object. In someembodiments, the 3D object comprises a large hanging structure (e.g.,wire, ledge, or shelf). Large may be a 3D object having a fundamentallength scale of at least about 1 centimeter (cm), 1.5 cm, 2 cm, 10 cm,20 cm, 30 cm, 40 cm, 50 cm, 60 cm, 70 cm, 80 cm, 90 cm, 1 m, 2 m, 3 m, 4m, 5 m, 10 m, 50 m, 80 m, or 100 m. The hanging structure may be a thinstructure. The hanging structure may be a plane like structure (referredto herein as “three-dimensional plane,” or “3D plane”). The 3D plane mayhave a relatively small width as opposed to a relatively large surfacearea. For example, the 3D plane may have a small height relative to alarge horizontal plane. FIG. 27 shows an example of a 3D plane that isplanar. The 3D plane may be planar, curved, or assume an amorphous 3Dshape. The 3D plane may be a strip, a blade, or a ledge. The 3D planemay comprise a curvature. The 3D plane may be curved. The 3D plane maybe planar (e.g., flat). The 3D plane may have a shape of a curvingscarf.

In some embodiments, the 3D object comprises a first portion and asecond portion. The first portion may be connected to the rest of the 3Dobject at one, two, or three sides (e.g., as viewed from the top). Thesecond portion may be connected to the rest of the 3D object at one,two, or three sides (e.g., as viewed from the top). For example, thefirst and second portion may be connected to a (e.g., central) column,post, or wall of the 3D object. For example, the first and secondportion may be connected to an external cover that is a part of the 3Dobject. The first and/or second portion may be a wire or a 3D plane. Thefirst and/or second portion may be different from a wire or 3D plane.The first and/or second portion may be a blade (e.g., turbine orimpeller blade). The first portion may comprise a top surface. Top maybe in the direction away from the platform and/or opposite to thegravitational field. The second portion may comprise a bottom surface(e.g., bottom skin surface). Bottom may be in the direction towards theplatform and/or in the direction of the gravitational field. FIG. 41shows an example of a first (e.g., top) surface 4110 and a second (e.g.,bottom) surface 4120. At least a portion of the first and secondsurfaces are separated by a gap. At least a portion of the first surfaceis separated by at least a portion of the second surface (e.g., toconstitute a gap). The gap may be filled with pre-transformed ortransformed (e.g., and subsequently hardened) material during theformation of the 3D object. The second surface may be a bottom skinlayer. FIG. 41 shows an example of a vertical gap distance 4140 thatseparates the first surface 4110 from the second surface 4120. Thevertical gap distance may be equal to the distance disclosed hereinbetween two adjacent 3D planes. The vertical gap distance may be equalto the vertical distance of the gap as disclosed herein.

Point A may reside on the top surface of the first portion. Point B mayreside on the bottom surface of the second portion. The second portionmay be a cavity ceiling or hanging structure as part of the 3D object.Point B may reside above point A. The gap may be the (e.g., shortest)distance (e.g., vertical distance) between points A and B. FIG. 41 showsan example of the gap 4140 that constitutes the shortest distance d_(AB)between points A and B. There may be a first normal to the bottomsurface of the second portion at point B. FIG. 41 shows an example of afirst normal 4112 to the surface 4120 at point B. The angle between thefirst normal 4112 and a direction of the gravitational accelerationvector 4100 (e.g., direction of the gravitational field) may be anyangle γ. Point C may reside on the bottom surface of the second portion.There may be a second normal to the bottom surface of the second portionat point C. FIG. 41 shows an example of the second normal 4122 to thesurface 4120 at point C. The angle between the second normal 4122 andthe direction of the gravitational acceleration vector 4100 may be anyangle δ. Vectors 4111, and 4121 are parallel to the gravitationalacceleration vector 4100. The angles γ and δ may be the same ordifferent. The angle between the first normal 4112 and/or the secondnormal 4122 to the direction of the gravitational acceleration vector4100 may be any angle alpha. The angle between the first normal 4112and/or the second normal 4122 with respect to the normal to thesubstrate may be any angle alpha. The angles γ and δ may be any anglealpha. For example, alpha may be at most about 45°, 40°, 30°, 20°, 10°,5°, 3°, 2°, 1°, or 0.5°. The shortest distance between points B and Cmay be any value of the auxiliary support feature spacing distancementioned herein. For example, the shortest distance BC (e.g., d_(BC))may be at least about 0.1 millimeters (mm), 0.5 mm, 1 mm, 1.5 mm, 2 mm,3 mm, 4 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm 35 mm, 40 mm, 50 mm,100 mm, 200 mm, 300 mm, 400 mm, or 500 mm. As another example, theshortest distance BC may be at most about 500 mm, 400 mm, 300 mm, 200mm, 100 mm, 50 mm, 40 mm, 35 mm, 30 mm, 25 mm, 20 mm, 15 mm, 10 mm, 5mm, 4 mm, 3 mm, 2 mm, 1.5 mm, 1 mm, 0.5 mm, or 0.1 mm. FIG. 41 shows anexample of the shortest distance BC (e.g., 4130, d_(BC)).

In some instances, it is desired to control the way at least a portionof a layer of hardened material is formed. The layer of hardenedmaterial may comprise a multiplicity of melt pools. The FLS (e.g.,depth, or diameter) of the melt pool may be at least about 0.5 μm, 1 μm,5 μm, 10 μm, 20 μm, 30 μm, 40 μm, or 50 μm. The FLS of the melt pool maybe at most about 0.5 μm, 1 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, or 50μm. The FLS of the melt pool may be any value between theafore-mentioned values (e.g., from about 0.5 μm to about 50 μm, fromabout 0.5 μm to about 10 μm, from about 10 μm to about 30 μm, or fromabout 30 μm to about 50 μm.

In some instances, it is desired to control one or more characteristicsof the fabricated 3D object (e.g., or portions thereof). For example, itmay be desired to control a hanging structure (e.g., ceiling of a cavityor ledge) as part of the 3D object. The 3D printing methods describedherein may utilize at least one of a tiling energy flux and a scanningenergy beam (collectively referred to herein as “irradiated energy”).The tiling energy flux and the scanning energy beam may differ by atleast one irradiated energy characteristics. For example, the tilingenergy flux and the scanning energy beam differ in their cross section(e.g., with the tiling energy flux having a larger cross section thanthe scanning energy beam). For example, the tiling energy flux and thescanning energy beam differ in their power density (e.g., with thetiling energy flux having a lower power density than the scanning energybeam). For example, the tiling energy flux and the scanning energy beamdiffer in their focus (e.g., with the scanning energy source being morefocused than the tiling energy flux). For example, the tiling energyflux and the scanning energy beam differ in their path trajectory whilegenerating (e.g., directly or indirectly) a layer of hardened material(e.g., with the tiling energy flux traveling along the path of tiletrajectory, whereas the scanning energy beam hatches along anothertrajectory). For example, the tiling energy flux and the scanning energybeam differ in the portions of transformed and/or hardened material theygenerate on forming a layer of transformed and/or hardened material aspart of the 3D object (e.g., with the tiling energy flux forming a firstportion of transformed material, whereas the scanning energy beam formsa second portion of transformed material that may or may not connect, oroverlap). Both the tiling energy flux and the scanning energy becollimated. Both tiling energy flux and scanning energy source may begenerated by the same (e.g., type of) energy source. Both tiling energyflux and scanning energy source may be directed by the same (e.g., typeof) scanner. Both tiling energy flux and scanning energy source maytravel through by the same (e.g., type of) optical window.

In some instances, it is desired to control one or more characteristicsof the melt pools that forms the layer of hardened material. Thecharacteristics may comprise the depth of a melt pool, microstructure,or the repertoire of microstructures of the melt pool. Themicrostructure of the melt pool may comprise the crystalline structure,or crystalline structure repertoire that is included in the melt pool.In some instances, a greater control over the one or morecharacteristics of the melt pool makes use of (i) a technique that willbe referred to herein as “flash heating,” (ii) a technique that isreferred to herein as “deep tiling,” (iii) a technique that is referredherein as “shallow tiling.” The flash heating and/or deep tiling methodsallows, for example, control of microstructure(s) formed by cooling of alocally heated and/or transformed material. Flash heating is focused onthe lateral (e.g., horizontal) spread of the irradiated energy in thematerial bed (e.g., and the 3D objet within). Deep tiling focuses on thedepth to which the irradiating energy penetrates the material bed (e.g.,and 3D object within). The irradiation methodology may comprise flashheating or deep tiling. In an embodiment, the irradiation methodincludes both deep tiling and flash heating (e.g., the irradiationenergy penetrates deep into the 3D object and considerably spreadslaterally around the melt pool). In some examples, considerably is atleast about 2, 3, 4, 5, 6, 7, or 10 melt pool fundamental length scales(e.g., diameters) away from the melt pool center formed by theirradiating energy.

In some embodiments, the tiling method (e.g., deep tiling and/or shallowtiling) comprises heating at least a portion of a material bed, and/or apreviously formed area of hardened material using at least one energysource which will be referred to herein as the “tiling energy source.”FIG. 36 shows an example of an energy beam 3601 that irradiates layersof hardened material that were previously formed (e.g., 3603 representsa layer of hardened material), which together make up a 3D object thatis disposed on a platform 3607. The heated area is schematically shownin the example of 3602. In some embodiments, the heated area maycomprise an area of transformed material. The heated area may encompassthe bottom skin layer. The heated area may comprise a heat affectedzone. The heated area may allow a parallel position at the bottom skinlayer to reach an elevated temperature that is above the solidustemperature (e.g., and at or below the liquidus temperature) of thematerial at the bottom skin layer, transform (e.g., sinter or melt),become liquidus, and/or plastically yield. For example, the heated areamay allow the layers comprising the bottom skin layer to reach anelevated temperature that is above the solidus temperature of thematerial (e.g., and at or below the liquidus temperature of the materialat the previously formed layer such as the bottom skin layer),transform, become liquidus, and/or plastically yield (e.g., in the deeptiling process). Flash heating may be done with the tiling energy beam.

A tile, as understood herein, is a portion of material (e.g.,transformed and/or hardened) that is generated or heated by the tilingenergy flux or by the scanning energy beam. In some examples, the tilingenergy source generates the tiling energy flux. The tiling energy sourcemay generate an energy beam. The tiling energy source may be a radiativeenergy source. The tiling energy source may be a dispersive energysource. The tiling energy source may generate a substantially uniform(e.g., homogenous) energy stream. The tiling energy source may generatea substantially uniform (e.g., homogenous) energy stream at least acrossthe beam area that forms the tile. The tiling energy source may compriseat least a portion of a cross section (e.g., and/or footprint on atarget surface) having a substantially homogenous fluence. The energygenerated by the tiling energy source is referred herein as the “tilingenergy flux.” The tiling energy flux may heat a portion of a 3D object(e.g., an exposed surface of the 3D object). The tiling energy flux mayheat a portion of the material bed. The portion of the material bed maycomprise an exposed surface portion of the material bed and/or a deeperportion of the material bed that is not exposed). Heating by the tilingenergy flux may be substantially uniform at least in the beam area thatforms the tile. In an example, the material bed is a powder bed.

In an embodiment, the tilling energy flux irradiates (e.g., flashes,flares, shines, or streams to) a position on the target surface for atime-period (e.g., predetermined time-period). The time in which thetiling energy flux (e.g., beam) irradiates is referred to herein as a“dwell time” of the tiling energy flux. The heat irradiation may befurther transmitted form the heated tile, for example, to adjacentportions of the material bed. During this time-period (e.g., ofirradiating the tile), the tiling energy flux may be (e.g.,substantially) stationary. During that time-period, the tiling energymay (e.g., substantially) not translate (e.g., neither in a raster formnor in a vector form). During this time-period the energy density of thetiling energy flux may be (e.g., substantially) constant. In someembodiments, during this time-period the energy density of the tilingenergy flux may vary. The variation may be predetermined. The variationmay be controlled (e.g., by a controller and/or manually). Thecontroller may determine the variation based on a signal received by oneor more sensors. The controller may determine the variation based on analgorithm. The controlled variation may comprise a closed loop or openloop control. For example, the variation may be determined based ontemperature and/or imaging measurements, among other sensed signals. Thevariation may be determined by melt pool FLS (e.g., size) evaluation.The variation may be determined based on height measurements of theforming 3D object.

In some embodiments, substantially stationary comprise spatialoscillations that are smaller than the FLS (e.g., diameter) of theenergy beam. The spatial oscillation may be in a range that is smallerthan (i) the diameter of the cross section of the energy beam, and/or(ii) of the diameter equivalent of the footprint of the energy beam onthe target surface. For example, the spatial oscillation range of theenergy beam can be at most 90%, 80%, 60%, 50%, 40%, 30%, 20%, 10%, 5%,1% or 0.5% of the diameter (i) of the cross section of the energy beam,and/or (ii) of the diameter equivalent of the footprint of the energybeam on the target surface. The energy beam may be the tiling energyflux and/or the scanning energy beam. Spatial oscillation is anoscillation in space (e.g., with respect to the target surface). Spatialoscillation may be oscillations in the location of the energy beam(e.g., with respect to the target surface). The spatial oscillation maybe in the location of the irradiated beam. The spatial oscillations maybe along the general movement direction of the irradiated energy (e.g.,along the hatch. E.g., along the path of tiles); for example, thespatial oscillations may comprise back and forth movement of theirradiated energy; for example, the spatial oscillations may be in anaxis parallel to the general direction of movement of the irradiatedenergy. The spatial oscillations may be along a direction that isperpendicular to the general movement direction of the irradiatedenergy; for example, side to side movement (e.g., FIG. 7, 702) withrespect to the general direction of movement of the irradiated energy(e.g., 701); for example, the spatial oscillations may be in an axisperpendicular to the general direction of movement of the irradiatedenergy. The spatial oscillations may be along an axis forming any angle(e.g., that is not perpendicular or parallel) with the general movementdirection of the irradiated energy, for example, side to side movementwith respect to the general direction of movement of the irradiatedenergy.

In an example, the tilling energy flux irradiates a position on thetarget surface for a time-period (e.g., predetermined) to form theheated tile with (e.g., having) a constant or variable power density(i.e., power per unit area) of the tiling energy flux. The targetsurface may be an exposed surface of the material bed, platform, 3Dobject (e.g., forming 3D object), or any combination thereof. In someembodiments, the variation in the power density comprises an initialincrease in power density of the tiling energy flux, followed by adecrease in the power density. For example, the variation may compriseinitial increase in the power density of the tiling energy flux,followed by a plateau, and a subsequent decrease in the power density.The increase and/or decrease in the power density of the tiling energyflux may be linear, logarithmic, exponential, polynomial, or anycombination or permutation thereof. The plateau may comprise of a (e.g.,substantially) constant energy density. The manner of (e.g., functionused in) the variation in the power density of the tiling energy fluxmay be influenced by (i) a measurement (e.g., a signal of the one ormore sensors), (ii) theory (e.g., by simulation), (iii) or anycombination thereof. The duration and/or peak of the power densityplateau of the tiling energy flux may be influenced by (i) a measurement(e.g., a signal of the one or more sensors), (ii) theory (e.g., bysimulations), (iii) or any combination thereof.

In some embodiments, the tiling energy flux has an extended crosssection. For example, the tiling energy flux has a FLS (e.g., crosssection) that is larger than the scanning energy beam. The FLS of across section of the tiling energy flux may be at least about 0.2millimeters (mm), 0.3 mm, 0.4 mm, 0.5 mm, 0.8 mm, 1 mm, 1.5 mm, 2 mm,2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm. The FLS of a cross sectionof the tiling energy flux may be between any of the afore-mentionedvalues (e.g., from about 0.2 mm to about 5 mm, from about 0.3 mm toabout 2.5 mm, or from about 2.5 mm to about 5 mm). The cross section ofthe energy beam can be at least about 0.1 millimeter squared (mm²), or0.2. The diameter of the energy beam can be at least about 300micrometers, 500 micrometers, or 600 micrometers. The distance betweenthe first position and the second position can be at least about 100micrometers, 200 micrometers, or 250 micrometers. %% The FLS may bemeasured at full width half maximum intensity of the energy beam. Insome embodiments, the tiling energy flux is a focused energy beam. Insome embodiments, the tiling energy flux is a defocused energy beam. Theenergy profile of the tiling energy flux may be (e.g., substantially)uniform (e.g., in the beam cross sectional area that forms the tile).The energy profile of the tiling energy flux may be (e.g.,substantially) uniform during the exposure time (e.g., also referred toherein as tiling time, or dwell time). The exposure time (e.g., at thetarget surface) of the tiling energy flux may be at least about 0.1milliseconds (msec), 0.5 msec, 1 msec, 10 msec, 20 msec, 30 msec, 40msec, 50 msec, 60 msec, 70 msec, 80 msec, 90 msec, 100 msec, 200 msec,400 msec, 500 msec, 1000 msec, 2500 msec, or 5000 msec. The exposuretime (e.g., at the target surface) of the tiling energy flux may be atmost about 10 msec, 20 msec, 30 msec, 40 msec, 50 msec, 60 msec, 70msec, 80 msec, 90 msec, 100 msec, 200 msec, 400 msec, 500 msec, 1000msec, 2500 msec, or 5000 msec. The exposure time may be between any ofthe above-mentioned exposure times (e.g., from about 0.1 msec to about5000 msec, from about 0.1 to about 1 msec, from about 1 msec to about 50msec, from about 50 msec to about 100 msec, from about 100 msec to about1000 msec, from about 20 msec to about 200 msec, or from about 1000 msecto about 5000 msec). The exposure time may be the dwell time. The powerper unit area of the tiling energy flux may be at least about 100 Wattsper millimeter square (W/mm²), 200 W/mm², 300 W/mm², 400 W/mm², 500W/mm², 600 W/mm², 700 W/mm², 800 W/mm², 900 W/mm², 1000 W/mm², 2000W/mm², 3000 W/mm², 5000 W/mm2, or 7000 W/mm². The power per unit area ofthe tiling energy flux may be at most about 100 W/mm², 200 W/mm², 300W/mm², 400 W/mm², 500 W/mm², 600 W/mm², 700 W/mm², 800 W/mm², 900 W/mm²,1000 W/mm², 2000 W/mm², 3000 W/mm², 5000 W/mm², 7000 W/mm², 8000 W/mm²,9000 W/mm², or 10000 W/mm². The power per unit area of the tiling energyflux may be any value between the afore-mentioned values (e.g., fromabout 100 W/mm² to about 3000 W/mm², from about 100 W/mm² to about 5000W/mm², from about 100 W/mm² to about 9000 W/mm², from about 100 W/mm² toabout 500 W/mm², from about 500 W/mm² to about 3000 W/mm², from about1000 W/mm² to about 7000 W/mm², or from about 500 W/mm² to about 8000W/mm²). The tiling energy flux may emit energy stream towards the targetsurface in a step and repeat sequence.

In some embodiments, the tiling energy flux emits an energy streamtowards the target surface in a step and repeat type sequence toeffectuate the tile forming process. The tiling energy flux may compriseradiative heat, electromagnetic radiation, charge particle radiation(e.g., e-beam), or a plasma beam. The tiling energy source may comprisea heater (e.g., radiator or lamp), electromagnetic radiation generator(e.g., laser), charge particle radiation generator (e.g., electron gun),or a plasma generator. The tiling energy source may comprise a diodelaser. The tiling energy source may comprise s light emitting diodearray (or LED array). The tiling energy source may be any radiationsource disclosed herein. The tilling energy beam may be any energy beamdisclosed herein.

In some embodiments, the tiling energy flux irradiates a pre-transformedmaterial, a transformed material, and/or a hardened material. Thepre-transformed material may be disposed in a material bed (e.g., apowder bed). The pre-transformed material may be ejected onto the targetsurface. In some examples, the tiling energy flux irradiates a targetsurface. The tiling energy flux may additionally irradiate thepre-transformed material as it travels towards the target surface (e.g.,using a direct material deposition type 3D printing). The target surfacemay comprise a pre-transformed material, a transformed material, or ahardened material. The tiling energy source may generate a tiling energyflux direct (e.g., using an optical system) it on the target surface.The tiling energy flux may heat a portion of the target surface. Thetiling energy flux may transform a portion (e.g., fraction) of thetarget surface. The tiling energy flux may preheat the target surface(e.g., to be followed by the scanning energy beam that optionallytransforms at least a portion of the preheated surface). The tilingenergy flux may post heat the target surface (e.g., following atransformation of the target surface). The tiling energy flux may postheat the target surface (e.g., to reduce a cooling rate of the targetsurface). The heating may be at a specific location (e.g., where thetile is formed from pre-transformed material).

In some examples, the tile forming procedure comprises a wide exposurespace of the tiling energy flux (e.g., a wide footprint on the targetsurface). In some examples, the tile forming procedure comprises a longdwell time (e.g., exposure time) of the tiling energy flux, which dwelltime may be at least about 0.5 millisecond, 1 millisecond, 0.5 second, 1second, 0.5 minute, or 1 minute. The tiling energy flux may irradiatethe target surface for even longer periods of time (e.g., for example, 1hour, or 1 day). In principle, the tiling energy flux may have a dwelltime that is infinity. The tiling energy flux (e.g., FIG. 36, 3601) mayemit a low energy flux for a long time-period to transform portions ofpre-formed layers of hardened material (e.g., 3602). These pre-formedlayers of hardened material may be deep layers within the 3D object(e.g., FIG. 36, layer 3603). The tiling energy flux may emit a lowenergy flux to control the cooling rate of a position within a layer oftransformed material. The low cooling rate may control thesolidification (e.g., rate and/or microstructure) of the transformed(e.g., molten) material. For example, the low cooling rate may allowformation of crystals (e.g., single crystals) at specified locationwithin the layer that is included in the 3D object.

In some examples, the tiling energy flux transforms (e.g., melts) aportion of a 3D object (e.g., comprising an exposed surface of the 3Dobject), at a time-period. In some embodiments, the transformation maybe substantially uniform (e.g., in rate and/or microstructure). In someembodiments, the transformation may vary (e.g., in rate and/ormicrostructure). The substantially uniform heating may be akin to heatstamping of the target surface (e.g., a layer of hardened materialand/or of pre-transformed material) by the tiling energy flux. A crosssection of the heat stamp (also herein “heat tile”) may be (e.g.,substantially) similar to the footprint of the tiling energy flux, onthe target surface. The (e.g., substantially uniform) irradiation by thetiling energy flux may form heat tiles on the target surface.

FIG. 1 shows an example of a 3D printing system and apparatuses,including a tiling energy source 122 that emits a tiling energy flux119. The tiling energy flux may travel through an optical system (e.g.114. E.g., comprising an aperture, lens, mirror, or deflector) and/or anoptical window (e.g., 123) to irradiate a target surface. The opticalsystem may comprise a scanner. The target surface may be a portion of ahardened material 106 that was formed by transforming at least a portionof a pre-transformed material (e.g., disposed in a material bed 104, orstreamed towards a platform) by a scanning energy beam 101. The scanningenergy beam 101 is generated by an energy source 121. The generatedenergy beam may travel through an optical mechanism 120 (e.g., scanner)and/or an optical window 115.

In some examples, the tiling energy flux and the scanning energy beamtravel through the same optical window and/or through the same opticalsystem. FIG. 25 shows an example where the tiling energy flux 2519 isgenerated by an energy source 2522, and travels through an opticalsystem 2514; the scanning energy source 2521 generates a scanning energybeam 2508 which travels through an optical system 2524 and both travelthrough same optical window 2523 into the processing chamber 2516 toform the 3D object 2506 from a material bed 2504, while irradiating theexposed surface 2519 of the material bed, which material bed rests on aplatform comprising a substrate 2509 and a base 2502, which substrate isvertically translatable 2512 by an actuator 2505. The tiling energy flux2519 in the example of FIG. 25, has a larger cross section than thescanning energy beam 2508. In some embodiments, the tiling energy fluxand the scanning energy beam both travel through the same opticalsystem, albeit through different components within the optical systemand/or at different instances. In some embodiments, the tiling energyflux and the scanning energy beam travel through different opticalsystems (e.g., and through the same optical window). The tiling energyflux and the scanning energy beam may travel through the same ordifferent optical windows.

In some embodiments, the emitted radiative energy (e.g., FIG. 1, 119)travels through an aperture, deflector and/or other parts of an opticalsystem (e.g., schematically represented as FIG. 1, 114). At times, theaperture restricts the amount of energy generated by the tiling energysource which reaches the target surface. The aperture restriction mayredact (e.g., cut off, block, obstruct, or discontinue) the energy beamto form a desired shape of a footprint (e.g., that may form the tile).Redaction of the energy beam may comprise redaction of a cross-sectionor footprint of the energy beam. The restriction may redact the energybeam to form a redacted tile cross section. Examples of apertures areshown in FIGS. 2, 200, 210, and 220. The aperture may allow only aportion of the emitted tiling energy flux from the tiling energy source(e.g., 202, 212, or 222) to reach the target surface. Examples ofaperture holes are represented in 203, 213, and 223. The aperture mayinclude one opening or several openings (e.g., geometric shapes in 220).The cross section of the tiling energy flux may be seen in FIGS. 2, 201and 202, wherein 202 is the portion of the footprint that is blocked bythe aperture, and the section 202 is the part of the energy flux that isfree to travel past the aperture.

FIG. 9 shows an example of an optical mechanism within a 3D printingsystem: an energy source 906 irradiates energy (e.g., emits an energybeam) that travels between mirrors 905 that direct it through an opticalwindow 904 to a position on the target surface 902 (e.g., exposedsurface of a material bed). The irradiated energy may also be directlyprojected on the target surface, for example, irradiated energy (e.g.,and energy beam) 901 can be generated by an energy source 900 (e.g.,that may comprise an internal optical mechanism, such as within a laser)and be directly projected onto the target surface.

The hardened material may comprise at least a portion of one or more(e.g., a few) layers of hardened material disposed above a platformand/or a pre-transformed material (e.g., powder) disposed in thematerial bed. The one or more layers of hardened material may besusceptible to deformation during formation, or not susceptible todeformation during formation. The deformation may comprise bending,warping, arching, curving, twisting, balling, cracking, or dislocating.In some examples, the at least a portion of the one or more layers ofhardened material may comprise a ledge or a ceiling of a cavity. Thedeformation may arise, for example, when the formed 3D object (or aportion thereof) lacks auxiliary support structure(s), during thecooling process of the transformed material. The deformation may arise,for example, when the formed structure (e.g., 3D object or a portionthereof) floats anchorless in the material bed), during the coolingprocess of the transformed material.

The tiling energy flux may comprise (i) an extended exposure area, (ii)extended exposure time, (iii) low power density (e.g., power per unitarea) or (iv) an intensity profile that can fill an area with a flat(e.g., top head) energy profile. Extended may be in comparison with thescanning energy beam. The extended exposure time may be at least about 1millisecond and at most 100 milliseconds. In some embodiments, an energyprofile of the tiling energy source may exclude a Gaussian beam or roundtop beam. In some embodiments, an energy profile of the tiling energysource may include a Gaussian beam or round top beam. In someembodiments, the 3D printer comprises a first and/or second scanningenergy beams. In some embodiments, an energy profile of the first and/orsecond scanning energy may comprise a Gaussian energy beam. In someembodiments, an energy profile of the first and/or second scanningenergy may exclude a Gaussian energy beam. The first and/or secondscanning energy may have any cross-sectional shape comprising an ellipse(e.g., circle), or a polygon (e.g., as disclosed herein). The scanningenergy beam may have a cross section with a diameter of at least about50 micrometers (μm), 100 μm, 150 μm, 200 μm, or 250 μm. The scanningenergy may have a cross section with a diameter of at most about 60micrometers (μm), 100 μm, 150 μm, 200 μm, or 250 μm. The scanning energymay have a cross section with a diameter of any value between theafore-mentioned values (e.g., from about 50 μm to about 250 μm, fromabout 50 μm to about 150 μm, or from about 150 μm to about 250 μm). Thepower density (e.g., power per unit area) of the scanning energy beammay at least about 5000 W/mm², 10000 W/mm², 20000 W/mm², 30000 W/mm²,50000 W/mm², 60000 W/mm², 70000 W/mm², 80000 W/mm², 90000 W/mm², or100000 W/mm². The power density of the scanning energy beam may be atmost about 5000 W/mm², 10000 W/mm², 20000 W/mm², 30000 W/mm², 50000W/mm², 60000 W/mm², 70000 W/mm², 80000 W/mm², 90000 W/mm², or 100000W/mm². The power density of the scanning energy beam may be any valuebetween the afore-mentioned values (e.g., from about 5000 W/mm² to about100000 W/mm², from about 10000 W/mm² to about 50000 W/mm², or from about50000 W/mm² to about 100000 W/mm²). The scanning speed of the scanningenergy beam may be at least about 50 millimeters per second (mm/sec),100 mm/sec, 500 mm/sec, 1000 mm/sec, 2000 mm/sec, 3000 mm/sec, 4000mm/sec, or 50000 mm/sec. The scanning speed of the scanning energy beammay be at most about 50 mm/sec, 100 mm/sec, 500 mm/sec, 1000 mm/sec,2000 mm/sec, 3000 mm/sec, 4000 mm/sec, or 50000 mm/sec. The scanningspeed of the scanning energy beam may any value between theafore-mentioned values (e.g., from about 50 mm/sec to about 50000mm/sec, from about 50 mm/sec to about 3000 mm/sec, or from about 2000mm/sec to about 50000 mm/sec). The scanning energy beam may becontinuous or non-continuous (e.g., pulsing). In some embodiments, thescanning energy beam compensates for heat loss at the edges of thetarget surface after the heat tiling process (e.g., forming the tiles byutilizing the tiling energy flux).

In some embodiments, the tiling energy source is the same as thescanning energy source. In some embodiments, the tiling energy source isdifferent than the scanning energy source. FIG. 1 shows an example wherethe tiling energy source 122 is different from the scanning energysource 121. The tiling energy source may travel through an identical, ora different optical window than the scanning energy source. FIG. 1 showsan example where the tiling energy flux travels through one opticalwindow 123, and the scanning energy 101 travels through a second energywindow 115 that is different. The tiling energy source and/or scanningenergy source can be disposed within the enclosure, outside of theenclosure (e.g., as in FIG. 1), or within at least one wall of theenclosure. The optical mechanism through which the tiling energy fluxand/or the scanning energy beam travel can be disposed within theenclosure, outside of the enclosure, or within at least one wall of theenclosure (e.g., as in FIGS. 1, 123 and 115)

The energy profile of the energy flux (e.g. beam) may represent thespatial intensity profile of the energy flux (e.g., beam) at aparticular plane transverse to the beam propagation path. FIG. 24 showsexamples of energy flux profiles (e.g., energy as a function of distancefrom the center of the energy flux (e.g., beam)). The energy fluxprofile (e.g., energy beam profile) may be represented as the power orenergy of the energy flux plotted as a function of a distance within itscross section (e.g., that is perpendicular to its propagation path). Theenergy flux profile of the tiling energy flux may be substantiallyuniform (e.g., homogenous). The energy flux profile may correspond tothe tiling energy flux. The energy beam profile may correspond to theenergy profile of the first scanning energy beam and/or the secondscanning energy beam.

The system and/or apparatus may comprise an energy profile alterationdevice that evens (e.g., smooths, planarizes, or flattens) out anyirregularities in the energy flux profile. The system and/or apparatusmay comprise an energy profile alteration device that creates a moreuniform energy flux profile, in at least a portion of the energy profilecross section (e.g., relative to the center of the beam). The energyprofile alteration device may comprise an energy flux (e.g., beam)homogenizer. The homogenizer can comprise a mirror. The mirror may bemultifaceted. The mirror may comprise square facets. The mirror mayreflect the energy flux at various (e.g., different) angles to create abeam with a more uniform power across at least a portion (e.g., theentire) of the beam profile (e.g., resulting in a “top hat” profile), ascompared to the original (e.g., incoming) energy flux. The energyprofile alteration device may output a substantially evenly distributedpower/energy of the energy flux across an energy beam cross section(e.g., forming an energy flux profile), instead of its originalnon-evenly distributed energy flux profile shape (e.g., Gaussian shape).The energy profile alteration device may comprise an energy flux profileshaper (e.g., beam shaper). The energy profile alteration device maycreate a certain (e.g., predetermined) shape to the energy flux profile.The energy profile alteration device may spread the central concentratedenergy within the energy flux profile along the energy flux crosssection (e.g., FLS of the energy flux, or FLS of the tile (a.k.a“stamp”)). The energy profile alteration device may output a grainyenergy flux profile. The energy profile alteration device may comprise adispersive or partially transparent glass. The glass can be a frosted,milky, or murky glass. The energy profile alteration device may generatea blurry energy flux. The energy profile alteration device may generatea defocused energy flux, after which the energy flux that entered theenergy profile alteration device will emerge as an energy flux having amore homogenized energy flux profile.

In some examples, the apparatus and/or systems disclosed herein includean optical diffuser. The optical diffusion may create wave frontdistortion of an irradiated beam. The optical diffuser may comprise adigital phase mask. The optical diffuser may diffuse light substantiallyhomogenously. The optical diffuser may remove high intensity energy(e.g., light) distribution and form a more even distribution of lightacross the footprint of the energy beam and/or flux. The opticaldiffuser may reduce the intensity of the energy beam and/or flux (e.g.,act as a screen). For example, the optical diffuser may alter an energybeam with Gaussian profile, to an energy beam having a top-hat profile.The optical diffuser may comprise a diffuser wheel assembly. The energyprofile alteration device may comprise a diffuser-wheel (a.k.a.,diffusion-wheel). The diffuser-wheel may comprise a filter wheel. Thediffuser-wheel may comprise a filter or diffuser. The diffuser-wheel maycomprise multiple optical filters or multiple optical diffusers. Thefilters and/or diffusers in the diffuser-wheel may be arranged linearly,non-linearly, or any combination thereof. The energy profile alterationdevice and/or any of its components may be controlled (e.g., monitoredand/or regulated) by the controller, and be operatively coupled thereto.The diffuser-wheel may comprise one or more ports (e.g., opening and/orexit ports) from/to which an energy ray (e.g., beam and/or flux) cantravel. The diffuser-wheel may comprise a panel. The panel may block(e.g., entirely or partially) the energy ray. The energy profilealteration device may comprise a shutter wheel. In some examples, thediffuser-wheel rotates. In some examples, the diffuser-wheel switches(e.g., alternate) between several positions. A position of thediffuser-wheel may correspond to an optical filter. The filter may bemaintained during the formation of a layer of hardened material. Thefilter may change during the formation of a layer of hardened material.The diffuser-wheel may change between position during the formation of alayer of hardened material (e.g., change between at least 2, 3, 4, 5, 6,7 positions). The diffuser-wheel may maintain a position during theformation of a layer of hardened material. At times, during theformation of a 3D object, some positions of the diffuser-wheel may notbe used. At times, during the formation of a 3D object, all thepositions of the diffuser-wheel may be used. During the formation of the3D object comprises during the formation of a layer of hardenedmaterial.

In some embodiments, the energy profile alteration device comprises aMicro Lens Array. The micro lens (also herein “microlens”) may have aFLS (e.g., diameter) of at most about 5 μm, 10 μm, 50 μm, 100 μm, 250μm, 500 μm, 750 μm, 1 mm, 5 mm, or 10 mm. The micro lens (also herein“microlens”) may have a FLS of at least about 5 μm, 10 μm, 50 μm, 100μm, 250 μm, 500 μm, 750 μm, 1 mm, or 5 mm. The micro lens (also herein“microlens”) may have a FLS of any value between the afore-mentionedvalues (e.g., from about 5 μm to about 5 mm, from about 5 μm to about750 μm, from about 750 μm to about 1 mm, or from about 1 mm to about 5mm). The microlens may include an element comprising a plane surfaceand/or a spherical convex surface (e.g., that refracts the light). Themicrolens may comprise an aspherical surface. The microlens may compriseone or more layers of optical material (e.g., to achieve a designperformance). The microlens may comprise one, two, or more flat andparallel surfaces. In some instances, the focusing action of the energyprofile alteration device is obtained by a variation of a refractiveindex across the micro lens (e.g., gradient-index (GRIN) lens). Themicrolens may comprise a variation in refractive index and/or a surfaceshape that allows focusing of the energy flux. The microlens may focusthe energy flux by refraction in a set of concentric curved surfaces(e.g., micro-Fresnel lenses). The microlens may focus the energy flux bydiffraction (e.g., binary-optic microlens). The microlens may compriseone or more grooves. The one or more grooves may comprise stepped edgesor multi-levels. The stepped edges or multi-levels may affordapproximation of the desired energy flux profile shape. Microlens arrayscan contain multiple lenses formed in a one-dimensional,two-dimensional, or three-dimensional array (e.g., on a supportingsubstrate). When the individual micro lenses have circular apertures,and are not allowed to overlap, they may be placed in a hexagonal arrayto obtain maximum coverage of the substrate. The energy profilealteration device may comprise non-circular apertures (e.g., to reduceeffects formed by any gaps between the lenses). The microlens (e.g.,microlens array) may focus and/or concentrate the energy flux onto atarget surface.

FIG. 40 shows an example of an optical path comprising an irradiatedenergy beam 4001 that travels through a diverging lens 4020, isconsequently focused by a focusing lens 4040, and reflected by a mirror4060 to project on a target surface 4000. Along the beam path from itsprojection until the mirror 4060, one or more optical diffusers (e.g.,4010, 4030, or 4050). FIG. 40, 4012 shows a vertical cross section of anoptical diffuser comprising planes disposed in various (e.g., different)angles 4013 that cause a beam to diffuse. FIG. 40, 4011 shows a verticalcross section of an optical diffuser comprising microlenses 4014. FIG.40, 4070 shows a cross section of an optical diffuser comprising variousoptical diffusers (e.g., 4071, and 4072), an open slot 4073 that allowsthe irradiated energy to pass through without being diffused, and aclosed slot 4074 that does not allow the irradiated energy to passthrough. The diffuser wheel may comprise one or more filters. Theoptical diffuser may create wave front distortion of the irradiatedenergy.

The energy flux has an energy profile. The energy flux (e.g., tilingenergy flux and/or scanning energy beam) may have any of the energy fluxprofiles in FIG. 24, wherein the “center” designates the center of thetile. The energy flux profile may be substantially uniform. The energyflux profile may comprise a substantially uniform section. The energyflux profile may deviate from uniformity. The energy flux profile may benon-uniform. The energy flux profile may have a shape that facilitatessubstantially uniform heating of the tile (e.g., substantially allpoints within the tile (e.g., including its rim)). The energy fluxprofile may have a shape that facilitates substantially uniformtemperature variation of the tile (e.g., at substantially all pointswithin the tile (e.g., including its rim)). The energy flux profile mayhave a shape that facilitates substantially uniform phase of the tile(e.g., substantially all points within the tile (e.g., including itsrim)). For example, the phase can be liquid or solid. Substantiallyuniform may be substantially similar, even, homogenous, invariable,consistent, and/or equal.

In an example, the energy flux profile of the tiling energy fluxcomprises a square shaped beam. In some instances, the tiling energyflux may deviate from a square shaped beam. In some examples, the tilingenergy flux excludes a Gaussian shaped beam (e.g., 2401). The shape ofthe energy flux (e.g., beam) may be the energy profile of the energyflux with respect to a distance from its center. The center can be acenter of the energy footprint, cross section, and/or tile. Thefootprint may on the target surface. The energy flux profile maycomprise one or more planar sections. FIG. 24, 2422 is an example of twoplanar sections of energy profile 2421. FIG. 24, 2432 is an example of aplanar section of energy profile 2431. FIG. 24, 2442 is an example oftwo planar sections of energy profile 2441. The energy flux profile maycomprise of a gradually increasing and/or decreasing section. FIG. 24,2410 shows an example of an energy profile 2411 comprising a graduallyincreasing section 2412, and a gradually decreasing section 2413. Theenergy flux profile may comprise an abruptly increasing and/ordecreasing sections. FIG. 24, 2420 shows an example of an energy profile2421 comprising an abruptly increasing section 2423 and an abruptlydecreasing section 4224. The energy flux profile may comprise a sectionwherein the energy flux profile deviates from planarity. FIG. 24, 2440shows an example of an energy profile 2441 comprising an energy fluxprofile comprising a section 2443 that deviates from planarity (e.g., bya distance “h” of average flux profile 2440). The energy profile of theenergy flux may comprise a section of fluctuating energy (e.g., power)profile. The fluctuation may deviate from an average planar energy(e.g., power) profile of the energy flux profile. FIG. 24, 2450 shows anexample of an energy flux profile 2451 comprising a fluctuating powersection 2452. The fluctuating section 2452 deviates from the averageflat power profile. The average planar power profile may be referred tousing the average power of that surface from an average baseline (e.g.,FIG. 24, “H” of energy flux profile 2450), by a +/− distance of “h” ofenergy flux profile 2450. The deviation (e.g., type and/or amount) fromplanarity of the energy flux profile may relate to the temperature ofthe target surface (e.g., and/or material bed). The deviation (e.g., apercentage of deviation) may be calculated with respect to an averagetop surface of the energy beam profile. The percentage deviation may becalculated according to the mathematical formula 100*(H−h)/H), where thesymbol “*” designates the mathematical operation “multiplied by.” Insome examples, when the material bed is at a temperature of below 500°C., the deviation may be at most 1%, 5%, 10%, 15%, or 20%. In someexamples, the first scanning energy beam and/or the second scanningenergy beam may have energy flux profile characteristics of the tilingenergy flux (e.g., as delineated herein).

In some examples, when the material bed is at a temperature of below500° C., the deviation may be by any value between the afore-mentionedvalues (e.g., from about 1% to about 20%, from about 10% to about 20%,or from about 5% to about 15%). When the material bed is from about 500°C. to below about 1000° C., the deviation may be at most 10%, 15%, 20%,25%, or 30%). When the material bed is from about 500° C. to below about1000° C., the deviation may be by any value between the afore-mentionedvalues (e.g., from about 10% to about 30%, from about 20% to about 30%,or from about 15% to about 25%). When the material bed is above about1000° C., the deviation may be at most 20%, 25%, 30%, 35%, or 40%). Whenthe material bed is of above about 1000° C., the deviation may be by anyvalue between the afore-mentioned values (e.g., from about 20% to about40%, from about 30% to about 40%, or from about 25% to about 35%). Below500° C. comprises ambient temperature, or room temperature (R.T.).Ambient refers to a condition to which people are generally accustomed.For example, ambient pressure may be 1 atmosphere. Ambient temperaturemay be a typical temperature to which humans are generally accustomed.For example, from about 0° C. to about 50° C., from about 15° C. toabout 30° C., from 16° C. to about 26° C., from about 20° C. to about25° C. “Room temperature” may be measured in a confined or in anon-confined space. For example, “room temperature” can be measured in aroom, an office, a factory, a vehicle, a container, or outdoors. Thevehicle may be a car, a truck, a bus, an airplane, a space shuttle, aspace ship, a ship, a boat, or any other vehicle. Room temperature mayrepresent the small range of temperatures at which the atmosphere feelsneither hot nor cold, approximately 24° C. it may denote 20° C., 25° C.,or any value from about 20° C. to about 25° C.

In some examples, the cross section of the tiling energy flux comprisesa vector shaped scanning beam (VSB). The energy flux may comprise avariable energy flux profile shape. The energy flux may comprise avariable cross sectional shape. The energy flux may comprise asubstantially non-variable energy flux profile shape. The energy fluxmay comprise a substantially non-variable cross sectional shape. Theenergy flux (e.g., VSB) may translate across the target surface (e.g.,directly) to one or more locations specified by vector coordinates. Theenergy flux (e.g., VSB) may irradiate once over those one or morelocations. The energy flux (e.g., VSB) may substantially not irradiate(or irradiated to a considerably lower extent) once between thelocations.

In some examples, a cross sectional shape of the tiling energy flux is(e.g., substantially) the shape of the tile. The shape of the tilingenergy flux cross section may substantially exclude a curvature. Forexample, the circumference of the tiling energy flux cross section, alsoknown as the edge of its cross section, or beam edge) may substantiallyexclude a curvature. The shape of an edge of the tiling energy flux may(e.g., substantially) comprise non-curved circumference. The shape ofthe tiling energy flux edge may comprise non-curved sides on itscircumference. The tiling energy flux edge can comprise a flat top beam(e.g., a top-hat beam). The tiling energy flux may have a substantiallyuniform energy density within its cross section. The beam may have asubstantially uniform fluence within its cross section. Substantiallyuniform may be nearly uniform. The beam may be formed by at least one(e.g., a multiplicity of) diffractive optical element, lens, deflector,aperture, or any combination thereof. The tiling energy flux thatreaches the target surface may originate from a Gaussian beam. Thetarget surface may be an exposed surface of the material bed and/or anexposed surface of a 3D object (or a portion thereof). The targetsurface may be an exposed surface of a layer of hardened material, or aplatform. The tiling energy flux may comprise a beam used in laserdrilling (e.g., of holes in printed circuit boards). The tiling energyflux may be similar to (e.g., of) the type of energy beam used in highpower laser systems (e.g., which use chains of optical amplifiers toproduce an intense beam). The tiling energy flux may comprise a shapedenergy beam such as a vector shaped beam (VSB). The tiling energy fluxmay be similar to (e.g., of) the type used in the process of generatingan electronic chip (e.g., for making the mask corresponding to thechip).

In some embodiments, the tiling energy source emits tiling energy fluxthat may slowly heat a tile within the exposed surface of a 3D object(e.g., FIG. 1, 106). Slowly may be in comparison to the scanning energybeam. The tile may correspond to a cross section (e.g., or footprint) ofthe tiling energy flux. The footprint may be on the target surface. Theradiative energy source may emit radiative energy that (e.g.,substantially) evenly heats a tile in the target surface (e.g., of a 3Dobject, FIG. 1, 106). FIG. 3 shows an example of a top view of twotarget surfaces 310 and 320 respectively. The target surface 310 isfilled with tiles that have been formed by irradiation (e.g., heating)by the tiling energy flux (e.g., 301). The target surface 320 is filledwith tiles that have been formed by irradiation (e.g., heating) by thetiling energy flux (e.g., 304).

The dimension (e.g., FLS) and/or shape of the tile may be varied withinthe target surface (e.g., a layer of powder material), and/or betweentarget surfaces (e.g., layers of powder material which are irradiated bythe tiling energy beam). The variation in the dimension and/or shape ofthe tile may depend on the geometry of the desired 3D object,deformation of at least a portion of the layer of hardened material thatis being formed, deformation of a previously formed layer of hardenedmaterial, or any combination thereof. The variation in the dimensionand/or shape of the tile may depend on the degree of a desireddeformation within the forming layer of hardened material. The degree ofdesired deformation may consider the ability of the layer of hardenedmaterial (e.g., that is forming) to resist future deformation (e.g., byformation of subsequent layers).

In some examples, the gradual irradiation by the (e.g., low powerdensity) tiling energy flux cause at least a portion of hardenedmaterial within the irradiated area (e.g., 301) to transform (e.g.,melt). In some instances, a uniformly heated area may be generated(e.g., 301). In some instances, a uniformly transformed (e.g., molten)area may be generated within the heated area. The tiles in the targetsurface may be heated sequentially, non-sequentially, at random, or in aseries. The sequence of heating may be determined for a single targetsurface or for several target surfaces (e.g., forming layers, or forminglayer portions). FIG. 4E shows an example of two surfaces which compriseheated tiles. In some examples, the sequence of heating (e.g.,generating) the tiles may correspond to the number sequence of thetiles. The heating sequence may consider the two target surfaces. Forexample, after tile 444 (in FIG. 4) is formed on surface 455, tile 445is formed on surface 456; then tile 447 is formed on surface 456,followed by forming tile 448 on surface 455.

At times, when transforming at least a fraction of the exposed surfacewithin (e.g., including the rim of) the tiles, the tiling energy fluxmay heat (e.g., transform) a corresponding fraction of the material atthe target surface and/or in an area beneath the target surface. Theheating may allow reaching an elevated temperature that is above thesolidus temperature of the material (e.g., and at or below its liquidustemperature), transforming (e.g., melting), liquefying, becomingliquidus, and/or plastic yielding of the heated layer of hardenedmaterial and/or one or more layers beneath the heated layer (e.g., thebottom skin layer). For example, the heating may penetrate one, two,three, four, five, six, seven, eight, nine, ten, or more layers of thehardened material (e.g., not only the layer that is exposed, but alsodeeper layers within the 3D object), or the entire 3D object (e.g., orunsupported portion thereof) reaching the bottom skin layer. Forexample, heating may penetrate one, two, three, four, five, six, seven,eight, nine, ten, or more layers of the pre-transformed material (e.g.,not only the layer that is exposed in the material bed, but also deeperlayers within the material bed), or the entire depth of the material bed(e.g., fuse the entire depth of the material bed). The very first formedlayer of hardened material in a 3D object is referred to herein as the“bottom skin.” In some embodiments, the bottom skin layer is the veryfirst layer in an unsupported portion of a 3D object. The unsupportedportion may not be supported by auxiliary supports. The unsupportedportion may be connected to the center (e.g., core) of the 3D object andmay not be otherwise supported by, or anchored to, the platform. Forexample, the unsupported portion may be a hanging structure (e.g., aledge) or a cavity ceiling.

In some embodiments, as the tile is being heated by the tiling energyflux, at least a fraction of the material within the tile area is beingtransformed. The transformed material fraction may contract into a shapethat is different from the shape of the tile. FIG. 12A shows an exampleof a heated tile 1210 that is heated to a point at which the area withinthe tile is transformed. The transformed material contracts (as shown bythe four small arrows that point towards 1211), which contractedfraction deviates from the tile structure 1210. The resultingtransformation will be the hardened material 1212. The tiles may berectangular, triangular, hexagonal, or any combination thereof. Therectangular tiles may comprise a parallelogram, a quadrilateral, anorthotope, or a square (e.g., a geometric shape).

In some embodiments, the tiles are arranged in a space-filling pattern.The space-filling pattern may comprise a herringbone, stacked bond,running bond, or basket weave pattern. The tile may be a polyform. Forexample, the tile may be a polyomino (i.e., a plane geometric shapeformed by joining one or more equal squares edge to edge). The tile maybe a polyabolo (i.e., a plane geometric shape composed of isoscelesright triangles joined along edges of the same length, also known as apolytan). The tiles may have a shape of a space-filling polygon. Thetiles may comprise a rectangle.

In some examples, the irradiated tiles deviate from the intended shapeof the hardened material tiles. For example, the tiles may compriseadditional expansions at each edge of the polygon. The expansions mayhave any shape (e.g., geometrical shape or a random shape). Theexpansion may experience a greater heat concentration at the edges ofthe polygon, as compared to a tile that does not have the edgeexpansions. FIG. 12B shows an example of a tile 1220 with expansions atits edges (e.g., 1223). The tile in FIG. 12B is composed of a main spacefiling polygonal tile (e.g., similar to the rectangular tile 1210),having smaller shapes at each of its edges (e.g., square 1223). The heatat the expanded edges may alter the shape of the transformed material(e.g., 1221) and facilitate a formation of a polygonal tile (or closerto that shape) of transformed and/or hardened material having thedesired polygonal shape (e.g., space filling polygon, 1222). The tilemay have a polygonal shape (e.g., space filling polygon). All the tileswithin an exposed surface may comprise a (e.g., substantially) identicalshape (e.g., FIG. 3). At least two of the tiles within an exposedsurface may comprise varied (e.g., different) shapes (e.g., FIG. 26,tiles 2601 and 2602).

In some examples, after, subsequent, or contemporaneous to the time whenthe tile is generated (e.g., heated to a predetermined temperatureand/or for a certain (e.g., predetermined) time) using the tiling energyflux, the scanning energy beam irradiates the areas adjacent to theedges of the tiles to increase the concentration of heat at the edges.FIG. 12C shows example of a tile 1230 that was heated by the tilingenergy flux, which edges were additionally heated with the scanningenergy beam (e.g., in a spiral shaped path 1233) to allow a greater heatdensity to accumulate (e.g., be present) at the edges of the polygonaltile. The greater heat at the edges may at least in part reduce thecontraction of the transformed material (e.g., 1231) and allow theformation of a polygonal tile (or closer to that shape) of transformedand/or hardened material (e.g., 1232) that has the desired crosssectional shape. The tile may comprise a curvature. The tile maycomprise an ellipse (e.g., round) shape.

In some instances, the tiles at least partially overlap each other in atarget surface. At times, the tiles may substantially overlap. Theoverlapped area may be at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%,80% or 90% of the average or mean tile area. The overlapped area may beat most about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90% of theaverage or mean tile area. The overlapped area may between any of theafore-mentioned values (e.g., from about 10% to about 90%, from about10% to about 50%, or from about 40% to about 90%) of the average or meantile area. The percentage of overlapped area may be substantiallyidentical along the path of the tiling energy flux. The percentage ofoverlapped area may be substantially identical in a generated layer ofhardened material. FIG. 30 shows examples of paths along which thetiling energy flux may travel (also herein “path-of-tiles.” E.g., 3040),forming tiles that partially overlap each other (e.g., 3030). Arrow 3010designates the direction along the path-of-tiles. Arrow 3020 designatesthe direction perpendicular to the path-of-tiles. The 3D object in frame3050 shows a top view of a 3D object that includes a bottom skin layer3060 on which a second layer (e.g., having tiles 3070) is generated withthe tiling energy flux traveling along the path-of-tiles, whichdirection of path-of-tile is visible by the lines formed in the secondlayer (e.g., having tiles 3070). The 3D object in frame 3050 is made ofInconel 718 and is formed from an Inconel powder bed by melting aportion thereof. The percentage of overlapped area may be substantiallyidentical along the path-of-tiles and between these paths (e.g., in thedirection 3020). The percentage of overlapped area may be substantiallyidentical along the path of the tiling energy flux (e.g., path-of-tiles)and perpendicular to that path. The percentage of overlapped area may bevaried along the path of the tiling energy flux. The percentage ofoverlapped area may be varied along the path of the tiling energy fluxand between paths. The percentage of overlapped area may be varied alongthe path of the tiling energy flux and perpendicular to that path. Thepercentage of overlapped area may be different along the path of thetiling energy flux. The percentage of overlapped area may be differentalong the path of the tiling energy flux and between paths. Thepercentage of overlapped area may be different along the path of thetiling energy flux and perpendicular to that path. For example, alongthe path, the tiles may overlap by at least about 60%, and between pathsor perpendicular to that path, the tiles may overlap by at least about30%. At times, the tiles may overlap more along the path, than betweenpaths. At times, the tiles may overlap more along the path, thanperpendicular to that path. At times, the tiles may overlap less alongthe path, than between paths. At times, the tiles may overlap less alongthe path, than perpendicular to that path. FIG. 30 shows an examplewhere the overlap of the formed tiles along the path is substantiallyidentical, the overlap of the formed tiles in a direction perpendicularto the path is substantially identical, and the overlap of the formedpath along the path is different from the overlap of the formed tilesperpendicular to the path. FIG. 30 shows an example where the overlap ofthe formed path along the path is greater than the overlap of the formedtiles perpendicular to that path. The path-of-tiles may be any pathdescribed herein for the energy beam (e.g., FIG. 8).

The adjacent and/or overlapping tiles may be formed using the tilingenergy flux. The sequence by which the tiling energy flux emits energyto the target surface as it proceeds along the path-of-tiles, maycomprise a dwell and intermission time. The intermission may be arelative intermission. For example, the intermission may comprise aperiod where a reduced amount of radiation (e.g., no radiation) isemitted by the tiling energy flux on the target surface along thepath-of-tiles. FIG. 32 shows two examples of a temperature profiles of atarget surface over time. In temperature profile 3210, the time at whicha position 3220 of a target surface is at a temperature above thetransformation temperature Tt is greater than the intermission time3250, where the temperature of a position on the target surface is belowTt. In temperature profile 3230, the time at which a position 3260 of atarget surface is at a temperature above the transformation temperatureTt is smaller than the intermission time 3240, where the temperature ofa position on the target surface is below Tt. The temperature profiledepicts the temperature of the target surface during the time in whichthe tiling energy flux travels along the path-of-tiles. The temperatureof the material at a particular position may be at or above thetransformation temperature of the material during the exposure time ofthe tiling energy flux (e.g., dwell time) when the tile is formed. Thetemperature of the material at a particular position may be below thetransformation temperature of the material during the intermission(e.g., “off time”) of the tiling energy flux, at which no tile isformed.

At least a portion of the target surface can be heated by the energysource (e.g., of the scanning energy beam and/or tiling energy flux).The portion of the material bed can be heated to a temperature that isgreater than or equal to a temperature wherein at least a portion of thetarget surface (e.g., comprising a pre-transformed material) istransformed. For example, the portion of the powder bed can be heated toa temperature that is greater than or equal to a temperature wherein atleast a portion of the powder material is transformed to a liquid state(referred to herein as the liquefying temperature) at a given pressure(e.g., ambient pressure). The liquefying temperature can be equal to aliquidus temperature where the entire material is at a liquid state at agiven pressure (e.g., ambient). The liquefying temperature of the powdermaterial can be the temperature at or above which at least part of thepowder material transitions from a solid to a liquid phase at a givenpressure (e.g., ambient). A powder material comprises a solidparticulate material.

The temperature and/or energy profile over time of the path-of-tiles maycomprise intermissions in which the path is irradiated with the tilingenergy flux with an energy that is insufficient to transform therespective portion of the target surface. For example, the path maycomprise intermissions in which the path is not irradiated with thetiling energy flux. During the intermission time, the tiling energy fluxmay travel elsewhere in the material bed and irradiate a differentportion of the target surface than along the subject path-of-tiles. Thatdifferent position may be a different tile or a different path-of-tiles.The different portion may be distant or adjacent to the path-of-tiles.

In some embodiments, the tiling energy flux may irradiate (e.g.,substantially) one position during the dwell time (within thepath-of-tiles) to form the tile. In some examples, the tiling energyflux remains along the path-of-tiles during the intermission. In someexamples, the tiling energy flux translates during the intermissions(e.g. off time) until it reaches a second dwell (e.g., irradiative)position. For example, during the intermission time, the tiling energyflux may travel elsewhere in the material bed and irradiate a differentportion of the material bed than the recently tiled position. Thedifferent portion may be distant or adjacent to the recently tiledposition (e.g., the tile that has just been formed). The tiling energyflux may dwell in substantially one position during the dwell timewithin the forming tile, and translate during the intermissions (e.g.off time) until it reaches the second dwell (e.g., irradiative)position. Melting may comprise complete melting into a liquid state.

The intermission time may allow the first formed tile to harden (e.g.,completely harden), prior to forming the second tile along the path oftiles. The intermission may allow at least the exposed surface of thefirst tile to harden (e.g., while its interior is still in a liquidstate), prior to forming the second tile along the path of tiles. Theintermission may allow at least the outer rim of the first tile toharden, prior to forming the second tile along the path of tiles. Theintermission may allow at least the exposed surface of the overlappingportion of the first tile to harden, prior to forming the second tilealong the path of tiles. In some examples, there is substantially nointermission between the dwell times. In some examples, the dwell timeof the tiling energy flux is continuous. The intermissions may comprisea reduced amount of radiation of the tiling energy flux. The reducedamount of radiation may not be sufficient to transform the portion ofthe material bed that is irradiated by the tiling energy flux during theintermission. The intermission can last at least about 1 msec, 10 msec,50 msec, 250 msec, or 500 msec. The intermission can last anytime-period between the afore-mentioned time-periods (e.g., from about 1msec to about 500 msec).

In some examples, the melt pool that is generated by the tiling energyflux is larger (e.g., have a larger FLS) than the melt pool generated bythe scanning energy beam. Larger may be in the horizontal and/orvertical direction. The melt pool that is generated by the tiling energyflux may have a FLS that is larger than the FLS of the melt poolgenerated by the energy beam by about 10%, 20%, 30%, 40%, 50%, 60%, 70%,70%, 80%, 90%, or 95%. The melt pool that is generated by the tilingenergy flux may have a FLS that is larger than the FLS of the melt poolgenerated by any value between the afore-mentioned values (e.g., fromabout 10% to about 95%, from about 10% to about 60%, from about 50% toabout 95%). The tiling energy flux may transform portions of previouslyformed layers. The tiling energy beam may form melt pools that span intopreviously formed layers (e.g., bottom skin). FIG. 36 shows an exampleof a vertical cross section of a 3D object made of Inconel 718, which 3Dobject includes a multiplicity of layers of hardened material formed bythe methods disclosed herein, wherein the melt pools that are lastlyformed (e.g., 3605), penetrate to previously formed layers; for example,to the bottom skin layer (e.g., 3606). FIGS. 39A-39B show examples of avertical cross section of various 3D objects formed of Inconel 718,which 3D object includes a multiplicity of layers of hardened materialformed by the methods disclosed herein. FIG. 39A shows an example of atwo-layered object that includes a bottom skin layer 3910 and a secondlayer 3911. The melt pools in the 3D object of FIG. 39A are hardlyvisible, since the entire 3D object is formed of very large melt poolsand reach the bottom skin layer. FIG. 39B shows an example of athree-layered objects that includes a bottom skin layer 3920 and twoadditional layers 3921. The melt pools in the 3D object of FIG. 39B arevery broad and reach the bottom skin layer.

In some examples, the tiling energy flux injects energy into one or morepre-formed layers (e.g., deeper layers) of hardened material that aredisposed below the target layer (e.g., layer of pre-transformedmaterial) that is irradiated by the tiling energy flux. The injection ofenergy into the one or more deeper layers may heat those deeper layersup. Heating of the deeper layers may allow those deeper layers torelease stress (e.g., elastically and/or plastically). For example, theheating of the deeper layers allows those layers to deform beyond thestress point. For example, the heating of the deeper layers may allow aposition of the deeper layer that is parallel to the irradiated positionto reach an elevated temperature that is above the solidus temperature(e.g., and at or below the liquidus temperature), liquefy (e.g., becomepartially liquid), transform (e.g., melt), become liquidus (e.g., fullyliquid), and/or plastically yield (e.g., stress-yield).

In some embodiments, the tiling energy flux is used at least in part informing the layers of hardened material that form the 3D object (e.g.,all the layers). In some embodiments, the tiling energy flux is used atleast in part in forming at least a portion of the layers of hardenedmaterial that form the 3D object (e.g., all the layers). The portion maybe the initial portion (e.g., layers in the first 1 or 2 millimeters ofthe 3D object). The portion may be up to a certain accumulated thicknessof the 3D object, referred to herein as the “critical layer thickness.”The certain critical layer thickness may be at least about 500 μm, 600μm, 700 μm, 800 μm, 900 μm, 1000 μm, 1200 μm, 1500 μm, 1800 μm, or 2000μm. The critical layer thickness may be of any value between theafore-mentioned values (e.g., from about 500 μm to about 2000 μm, from500 μm to 1000 μm, or from 800 μm to 2000 μm). The critical layerthickness may be a critical thickness above which at least anadditionally accumulated layer of hardened material will not contributesubstantial deformation of the 3D object (or portion thereof).Substantial deformation is relative to the intended purpose of the 3Dobject. The at least a portion may be devoid of auxiliary supports. Theat least a portion may float anchorlessly in the material bed during itsformation.

In some embodiments, the scanning energy beam is used at least in partin forming the layers of hardened material that form the 3D object(e.g., all the layers). The portion may be the later portion (e.g.,beyond the critical thickness). In some embodiments, the energy beam isused (e.g., at least in part) to form the bottom skin layer. In someembodiments, the energy beam is used to form the bottom skin layerwithout the use of the tiling energy flux. The portion may be from acertain accumulated thickness of the 3D object onwards. The energy beammay be using in forming a layer of hardened material in combination withthe tiling energy flux, alone, or without the aid of the tiling energyflux.

In some examples, the scanning energy beam forms a contour (e.g., FIG.21C, 2131; or FIG. 21A, 2111) of hardened material around at least aportion of the area to be filled with the path-of-tiles (e.g., FIG. 21C,2132) generated by the tiling energy flux and/or hatches made by thescanning energy beam (e.g., FIG. 21A, 2112). In some examples, thescanning energy beam propagates in hatches along the target surface. Thecontour may be a closed line or an open line (e.g., comprisingintermissions). The contour may be a continuous line or a discontinuousline. The contour may precede, supersede, or be formed contemporaneouslywith the formation of the interior tiles. FIGS. 21A-21D show examples oftop view of a layer of hardened material illustrating various possiblestages in the formation of a layer of hardened material. FIG. 21A showsan example where the contour 2111 and the hatches made by the scanningenergy beam (e.g., 2112) are made prior to forming the path-of-tiles.FIG. 21B shows an example of a completed layer of hardened material 2120comprising a contour 2121, hatching made by the scanning energy beam(e.g., 2122), and tiles may by the tiling energy flux (e.g., 2123). FIG.21C shows an example where the contour 2131 and the tiles (e.g., 2132)made by the tiling energy flux are made prior to forming the hatches.FIG. 21D shows an example of a completed layer of hardened material 2140comprising a contour 2141, hatches made by the scanning energy beam(e.g., 2142), and tiles may by the tiling energy flux that includecomplete tiles (e.g., 2143) and redacted tiles (e.g., 2144). The path oftiles may sequentially fill the entire target layer of hardened material(e.g., corresponding to a target slice of the 3D object model). In someexamples, the area to be filled with tiles may be separated to patches.The path of tiles may fill the entire target layer in patches. Thepatches may separate the sequence of filling the target space (e.g.corresponding to a target slice of the 3D object model) FIG. 21D can beused to illustrate an example of patch filling. For example, the tilesin patch B may be formed first, followed by forming tiles in patch A,then followed by forming the tiles in patch C, and finally followed bythe redacted patches (e.g., 2144). In the example of FIG. 21D, thelighter tiles belong to patch A, darkest tiles belong to patch C, andintermediate gray tile belong to patch B. Forming the tiles may followany ordering combination of patches. Forming the layer of hardenedmaterial may comprise forming a contour, hatches made by the scanningenergy beam, one or more patches of path-of-tiles, redacted tiles (e.g.,partial tiles, see FIG. 2), individual tiles, or any permutation orcombination thereof. In some examples, most of the area of the layer ofhardened material is formed from tiles (e.g., FIG. 21B, 2123). The tilesmay be formed by the tiling energy flux. In some embodiments, most ofthe area of the layer (e.g., horizontal cross section thereof) may be atleast about 51%, 60%, 70%, 80%, 90%, or 95% of the area of the layer. Insome examples, a minor part of the layer of hardened material is formedby hatching (e.g., 2122). The hatching may be formed by the scanningenergy beam. A minor part of the layer (e.g., horizontal cross sectionthereof) may be at most about 49%, 40%, 30%, 20%, 10%, 5%, or 1% of thearea of the layer.

In some examples, the tiles have a geometric shaped cross section. Thetile can comprise a cross-section (e.g., horizontal cross section) thatis circular, triangular, square, rectangular, pentagonal, hexagonal,partial shapes thereof, and/or combinations thereof. The tile cancomprise a polygonal cross-section. The tile cross section may be aparallelogram. The tiles on the target surface may comprise anycombination of tile shapes (e.g., that would tightly fill a space). Forexample, a combination of triangle and hexagon shaped tiles. The tilesin a first target surface and in a second target surface that isadjacent (e.g., above or below) to the first target surface may besubstantially aligned. The tiles in a first target surface and in asecond target surface that is adjacent (e.g., above or below) to thefirst target surface, may be substantially mis-aligned (e.g., may bearranged in a face centered cubic (FCC) or hexagonal closed packed (HCP)arrangement).

In some embodiments, the tiling methodology includes a step and repeatprocess. In some embodiments, the tiling methodology includes heating afirst area in a target surface, moving to a second area in the targetsurface, and heating the second area. The areal heating may utilize atiling energy flux that irradiates the area while (e.g., substantially)not moving, or a scanning energy beam that irradiates the area whilehatching it. The sequential heating of the target surface using thetiling methodology may follow a path. The path may include a path of thetiles in the layer (herein also “path-of-tiles”), which corresponds tothe sequence in which the portions (e.g., tiles) are heated. The tilesmay follow a vectorial path (e.g., a predesigned path). The tiles mayfollow a rasterized path. Heating may be to a temperature below, at, orabove a transformation temperature.

The path-of-tiles can be linear, rectilinear, curved, staggered,stochastic, or any combination thereof. The sequence may be assignedaccording to an algorithm. The algorithm may exclude a random numbergenerator. The algorithm may comprise the area-of-preclusion asdescribed herein. FIG. 4B shows an example of a sequence of severalpaths-of-tiles numbered 421-424. The direction of the arrows in each of421-424 designates the sequence in which a single file of individualtiles (e.g., 402-408) are heated (e.g., generated) in the layer 401. Forexample, the path-of-tiles 421 illustrates that tile 402 was heatedfirst, tiles 403, 404, 405, 406, and 407 were formed in sequence oneafter another, and 408 was heated last (e.g., the tiles were generatedin a single file). FIG. 4C shows an example of a path 431 thatdesignates the sequence in which individual portions (e.g., 402-408) aresequentially formed in the layer 401. FIG. 4D shows an example ofindividual portions (e.g., 402-408) generated in the layer 401 in amanner that excludes an area in the sequence of tile heating. Thesequence of tile forming may be the path-of-tiles. The excluded area maybe designated as “area of preclusion.” The path-of-tiles may be any pathdescribed herein for the energy beam.

In some examples, the cross sections of the tiles are heatedsequentially. At least two of the sequentially heated tiles (e.g., allthe sequential tiles) may touch each other, border each other, overlapeach other, or any combination thereof. The sequentially generated tilesmay touch or overlap each other at least at one of their edges. At leasttwo of the sequentially heated tiles (e.g., all the sequential portionsof material) may overlap. At least two of the sequentially generatedtiles (e.g., all the sequential tiles) may be separated by a gap. Thegenerated tiles may be formed in a random or non-random sequence. Thegenerated tiles may be formed in a manner that avoids an area ofpreclusion. The area of preclusion may comprise three or more tile areasthat are heated sequentially and are arranged on a straight line. Thedetermination of the area of preclusion may comprise characteristics ofa gap between at least two tiles (or lack thereof). The gapcharacteristics may include the height, length, width, or volume of thegap. The determination of the area of preclusion may comprisecharacteristics of the first layer of hardened material and anypreviously formed layers of hardened material, which characteristics mayinclude the height, length, width, volume, shape, or material of theselayer(s). The determination of the area of preclusion may compriseenergy characteristics of the first layer and any previously formedlayers, for example, energy depletion characteristics. FIG. 4A shows anexample of a first layer 401, on which sequential tiles are heated(e.g., generated), numbered 402-408, such that at least one of theiredges (e.g., two edges) are touching each other, forming a rowcomprising single file of tiles. The number sequence represents thesequence in which the tiles were heated, with 402 being the first tileheated in layer 401, and 408 the last respectively (e.g., 402, followedby 403, followed by 404, . . . followed by 408). FIG. 4D shows anexample of a first layer 401 in which tiles 442-450 are heated in amanner that avoids an area of preclusion, wherein the number sequencedesignates the sequence in which the tiles were disposed, with 442 beingthe first tile formed on layer 401, and 450 the last.

The layer of hardened material that comprises the heated (e.g., formed)tiles may utilize a symmetric or asymmetric path (e.g., path-of-tiling)for their heating. The tiling energy flux may form the tiles in asymmetric or asymmetric manner from a layer of pre-transformed material.During the generation of a layer of hardened material, the tiling energyflux may heat (e.g., form) the tiles in a symmetric or asymmetricmanner. For example, the symmetric manner comprises using a point, axisor plane of symmetry disposed substantially in the center of the area ofthe material bed to be transformed. FIG. 31 shows an example of a tileformation sequence. Per a point symmetry sequence, the tiling can beformed in the following order: 3110, 3140, 3120, 3150, 3130, and finally3160. Per a mirror symmetry sequence, the tiling can be formed in thefollowing order: 3110, 3150, 3120, 3140, 3160, and finally 3130. Per arotational symmetry, the tiling can be formed in the following order:3110, 3150, 3120, 3140, 3160, and finally 3130. An asymmetric sequencemay be formed when all the vectorial paths point towards a singledirection (e.g., FIG. 8, 814). Per a directional asymmetric tilingsequence, the tiling can be formed in the following order: 3110, 3120,3160, 3170, 3130, 3150, and finally 3140. In some examples, anasymmetric sequence results in a layer of hardened material (e.g., 3Dplane) that is bent (e.g., warped). In some examples, a symmetric tilingsequence results in a layer of hardened material (e.g., 3D plane) thatis substantially planar. The usage of symmetric tiling sequence mayreduce the amount of curvature (e.g., warping) in the formed layer ofhardened material. An example of a symmetric path may be a path-of-tilesthat comprises opposing vector paths (e.g., FIG. 8, 815), or aserpentine path (e.g., FIG. 8, 810). In some examples, the path-of-tilesis heated (e.g., formed) from the edge of the area to be tiled, towardsthe center of the area to be tiles (e.g., the edge of the formed layerof hardened material, towards its center). The inward boundpath-of-tiles sequence may reduce the curvature of the resulting layerof hardened material. The inward bound path-of-tiles may comprisesymmetric or asymmetric tiling sequence. Tile number 3170 in the exampleof FIG. 31, may be formed last following an inward bound path-of tilesequence, whereas the tiles 3110-3160 may be formed prior to theformation of tile 3170.

The heating (e.g., generation) of a tile may utilize irradiation of a(e.g., low power density) wide cross sectional tiling energy flux at(e.g., substantially) one position. Alternatively or additionally, thegeneration of a tile may utilize a (e.g., high power density) narrowcross sectional energy beam (e.g., scanning energy beam) that travelsalong hatches to generate the shape of the tile. In some embodiments,the path traveled by the tiling energy flux or by a first scanningenergy beam may be heated (to a temperature below transformationtemperature of the material) by a second scanning energy beam. Thesecond scanning energy beam may the same scanning energy beam that isused to generate the tile of transformed material. The second scanningenergy beam may a different scanning energy beam from the one used toform the tiles of transformed material (e.g., first scanning energybeam, or tiling energy flux). The second scanning energy beam may begenerated by a second scanning energy source. The second scanning energysource may be the same scanning energy source that is used to generatethe first scanning energy beam, or may be a different energy source. Thesecond scanning energy source may be the same scanning energy sourcethat is used to generate the tiling energy flux, or be a differentenergy source. In some embodiments, the tiling energy flux may heat (butnot transform) portions of the target surface, and the second energybeam may transform material within the heated tiles. The pre or posttransformation heating may reduce temperature gradients in the targetsurface, reduce deformation, and/or generate certain microstructure(s).The second scanning energy beam may be a substantially collimated beam(e.g., an electron beam or a laser). The second scanning energy beam maynot be a dispersed beam. The second scanning energy beam may follow apath. The path may form an internal path (e.g., vectorial path) withintarget surface portions during the formation of a layer of transformedmaterial (e.g., in a similar manner to the first energy beam). The pathmay form material-filled portions along the target surface.

In some embodiments, the tiling energy flux is used to heat portions ofthe target surface (i.e., tiles) to a temperature below thetransformation temperature, while the (e.g., second) energy beam is usedto transform material in these target surface portions (e.g., tiles). Insome embodiments, the scanning energy beam is used to heat portions ofthe target surface (i.e., tiles) to a temperature below thetransformation temperature, while the tiling energy flux is used totransform material in these target surface portions (e.g., tiles). Theheating to a temperature below the transformation temperature may bebefore by one energy radiation, after, and/or contemporaneous totransformation by the other energy radiation.

The path of the scanning energy beam within the tile cross section isdesignated herein as the “internal path” within the tiles. The internalpath within the tile cross section may be of substantially the samegeneral shape as the shape of the path-of-tiles (e.g., both sine waves).The internal path within the tiles may be of a different general shapethan the shape of the path-of-tiles (e.g., vector lines vs. a sinewave). FIG. 6E shows examples of the internal path within the tiles 641that follows a curved shape, and is disposed within a heated tile 640 inan exposed surface 601. FIG. 6D shows examples of the internal pathwithin the heated tile 602 in the exposed surface 601, which internalpath follows a non-curved (e.g., vectorial) shape. The path may follow aspiraling shape, or a random shape (e.g., FIG. 8, 811). FIG. 6G showsexamples of the internal path within the heated tile 602 in the exposedsurface 601 that has a spiraling shape (e.g., starting at position 680and ending at position 681). The path may be overlapping (e.g., FIG. 8,816) or non-overlapping. The path may comprise at least one overlap. Thepath may be substantially devoid of overlap (e.g., FIG. 8, 810).

The path of the scanning energy beam may comprise a finer path (e.g.,sub-path). The finer path may be an oscillating path. FIG. 7 shows anexample of a path of the scanning energy beam 701. The path 701 iscomposed of an oscillating sub-path 702. The oscillating sub path can bea zigzag or sinusoidal path. The finer path may include or substantiallyexclude a curvature.

The scanning energy beam may travel in a path that comprises or excludesa curvature. FIG. 8 shows various examples of paths. The scanning energybeam may travel in each of this type of paths. The path maysubstantially exclude a curvature (e.g., 812-815). The path may includea curvature (e.g., 810-811). The path may comprise hatching (e.g.,812-815). The hatching may be directed in the same direction (e.g., 812or 814). Every adjacent hatching may be directed in an oppositedirection (e.g., 813 or 815). The hatching may have the same length(e.g., 814 or 815). The hatching may have varied length (e.g., 812 or813). The spacing between two adjacent path sections may besubstantially identical (e.g., 810) or non-identical (e.g., 811). Thepath may comprise a repetitive feature (e.g., 810), or be substantiallynon-repetitive (e.g., 811). The path may comprise non-overlappingsections (e.g., 810), or overlapping sections (e.g., 816). The tile maycomprise a spiraling progression (e.g., 816). The non-tiled sections ofthe target surface (e.g., FIG. 21A, 2112) may be irradiated by thescanning energy beam in any of the path types (e.g., hatch types)described herein.

In some instances, it is not desired to allow the heated tiles to exceedthe rim of the exposed surface. At times, when the heated tiles exceedthe rim of the target surface (e.g., surface of a 3D object), theirradiated energy flux may heat the pre-transformed material (e.g.,powder) within the material bed adjacent to the target surface. Thatirradiated pre-transformed material may transform and/or adhere to the3D object. The irradiated pre-transformed material may form a sinteredstructure (e.g., that is unwanted) adjacent to (e.g., connected ordisconnected from) the 3D object. Heating the pre-transformed materialwithin the material bed may cause the pre-transformed material to atleast partially transform (e.g., melt, sinter, or cake).

The tiling process (e.g., deep tiling, shallow tiling, or flash heating)may be used to heat and/or transform at least a portion of an exposedlayer of a 3D object (e.g., comprising a hanging plane and/or wire).FIG. 3 shows an example of a top view of a plane 310 and a wire 320.

Some of the portion (e.g., heated portions, or tiles of hardenedmaterial) can be separated by a gap, touch each another heated tile,overlap each other, or any combination thereof. At least two tiles mayfuse to each other. One tile may be separated from a second tile by agap, while overlapping a third tile. For example, all the tiles may beseparated from each other by gaps. At least two gaps may besubstantially identical or different (e.g., in its FLS). Identical ordifferent can be in length, width, height, volume, or any combinationthereof. The gap size (e.g., height, length, and/or width) may be atmost about 30 μm, 35 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100μm, 150 μm, or 200 μm. The gap size may be any value between theafore-mentioned values (e.g., from about 30 μm to about 200 μm, fromabout 100 μm to about 200 μm, from about 30 μm to about 100 mm, fromabout 80 mm to about 150 mm).

In some instances, the process of heating portions of the target surfacecontinues until (e.g., substantially) all the gaps have been filled bytiles (e.g., except for the edge areas. E.g., FIG. 3, 302). Such processmay be referred herein as “Pointillism.” Any gaps and/or edges can befilled by an energy beam (e.g., following a path). The pointillismmethod may comprise an area of preclusion (e.g., exclude heating threetiles that are adjacently situated and form a line).

The heating can be done by the one or more energy sources. At least twoof the energy sources may heat target surface portions (i.e., tiles)simultaneously, sequentially, or a combination thereof. At least twotarget surface portions can be heated sequentially. At least two targetsurface portions can be heated (e.g., substantially) simultaneously. Thetime and/or special sequence of heating at least two of the targetsurface portions may overlap.

In some embodiments, the second heated tile area may be distant from thefirst heated tile area. The area can be a cross section. The heat fromthe first tile can negligently increase the temperature of the secondtile (e.g., before it is heated). Heating the first target surfaceportion may elevate the temperature of the second tile (e.g., before itis heated) in at most about 0.1%, 0.5%, 1%, 5%, 10%, 15%, or 20%.Heating the first tile may elevate the temperature of the second tile(e.g., before it is heated) by any percentage between theafore-mentioned percentages (e.g., from about 0.1% to about 20%, or fromabout 0.1% to about 10%). The heat from the first tile can negligentlyalter the dimension of the second tile (e.g., expand in length, width,height, and/or volume). Heating the first tile may alter the form (e.g.,dimension) of the target surface to be occupied by the second tile(e.g., before it is heated) by at most about 0.1%, 0.5%, 1%, 5%, 10%,15%, or 20%. Heating the first tile may alter the form of the targetsurface to be occupied by the second tile (e.g., before it is heated) byany percentage between the afore-mentioned percentages (e.g., from about0.1% to about 20%, or from about 0.1% to about 10%). The tile may be aportion of pre-transformed material, or a transformed material tile.

In some embodiments, no sequence of three tile is formed in a straightline (e.g., single file). The three tile can be heated (e.g.,transformed) sequentially such that the heating of the first tile isimmediately followed by the heating of the second tile, that is in turnimmediately followed by the heating of the third tile. In someembodiments, at least two of the three tiles are heated in parallel. Insome embodiments, at least two of the three tiles are heated in anoverlapping sequence. An example for an overlapping sequence ofdeposition of transformed material can be a first tile that is beingformed on the exposed surface (e.g., layer), and while it is beingformed, the second tile is beginning to form. The first tile can end itsformation before, during, or after the formation of the second tile. Insome embodiments, no sequence of three or more tiles that are situatedclose to each other (e.g., touching each other, or forming a gap (e.g.,as described herein) with each other) is heated (and/or generated) in astraight line. The three or more tiles can include at least 4, 5, 6, 7,8, 9, 10, 50, or 100 tiles. The three or more tiles can be any valuebetween the afore-mentioned values (e.g., from 4 tiles to 100 tiles,from 5 tiles to 10 tiles, from 10 tiles to 100 tiles, or from 7 tiles to50 tiles). “Between” as understood herein, is meant to be inclusive. Thethree or more tiles can exclude tiles that reached temperatureequilibrium (e.g., with the environment). The three or more tiles caninclude hot tiles (e.g., comprising transformed material). The three ormore tiles can comprise tiles that include transformed material and didnot completely harden (e.g., solidify). The three or more tiles canexclude tiles that comprised transformed material that hardened into ahardened (e.g., solid) material (e.g., after their heating). The threeor more tiles can include tiles that are disposed on a hot portion ofthe target surface. The three or more tiles can include tiles that aredisposed on a portion of the exposed target surface that did not reachtemperature equilibrium. The three or more tiles can exclude tiles thatare disposed on a portion of the hardened material that is no longersusceptible to deformation (e.g., since it is sufficiently cold). Insome embodiments, the area of preclusion may comprise a straight tilebetween two or more sequentially deposited tiles (e.g., when the twosequentially deposited tiles are in close proximity to each otherseparated by a gap, border each other, or overlap each other). Themethods, systems, and/or apparatuses describe herein may aim to at leastform successively (e.g., one after another) heated tiles in an area thatis outside the area of preclusion. In some embodiments, the area ofpreclusion may include two tiles that are disposed sequentially one nextto each other. Next to each other may be direct or indirect. Forexample, next to each other includes directly next to each other. Nextto each other comprises next to a tile face, vertex, or edge of thetile. Next to each other may comprise touching a file face, vertex, oredge. Next to each other may comprise indirectly next to each otherhaving a gap between the two tiles (e.g., any gap value disclosedherein).

In some examples, the area of preclusion depends on the temperature atvarious portions of the target surface, the time elapsed from heating atleast one of two or more previously heated tiles of the first layer, thetemperature at the potential area to be heated, the temperature gradientfrom at least one of the two or more prior tiles to the potential areato be heated, the temperature at the previously heated two or moreportions, the heat deformation susceptibility of the exposed area to beheated by a third tile, or any combination thereof. In some examples,the area of preclusion depends on the physical state of matter withinthe heated two or more tile (e.g., liquid, partially liquid, or solid).The two or more tiles and the third tile to be heated (and/or formed)may be situated on a straight line.

In some embodiments, successively heating three or more tiles of thefirst layer disposed in a straight line will cause the layer (e.g.,comprising the exposed surface) to deform (e.g., bend). The deformationmay be disruptive (e.g., for the intended purpose of the 3D object).Such straight line may form (e.g., generate, create) a line of weaknessin the first layer (e.g., layer of hardened material that is at least aportion of the 3D object). In some embodiments, successively heating atleast three portions of the first layer in a pattern that differs from astraight line (e.g., FIG. 4D) will substantially lessen the degree ofdeformation of the layer of hardened material as compared to astraight-line heating and/or generation pattern (e.g., FIG. 4A). In someembodiments, successively heating and/or generating at least three tilesof the first layer in a pattern that differs from a straight line willsubstantially not cause the first layer to deform (e.g., bend). In someembodiments, successively heating at least three portions of the firstlayer in a pattern that differs from a straight line will retard (orprevent) the formation of lines of weakness. In some embodiments,successively heating at least three tiles of material in the layer ofhardened material in a pattern that differs from a straight line (e.g.,single file) will substantially not cause the first layer to deform(e.g., bend). In some embodiments, successively heating at least threetiles of material on the first layer in a pattern that differs from astraight line will retard (or prevent) the formation of lines ofweakness.

FIGS. 5A-5F schematically show examples of a top view of parts of aversion of the Pointillism process. In this version, a tile oftransformed material is formed within a tile of heated material to atemperature below the transformation temperature. FIG. 5A shows anexample of a target surface (e.g., the exposed layer of a material bed)501. FIG. 5B shows an example of a tile of the target surface 501 thatthat is heated (i.e., 502) below the transformation temperature of thematerial. FIG. 5C shows an example of a fraction of material 503 that istransformed within the heated tile 502. FIG. 5D shows an example of asecond heated tile 504, and the previously formed tiles of transformedmaterial 503. FIG. 5E shows an example of a second fraction oftransformed material 505 within the heated tile 504, a third heated tile506, and the previously formed tiles of transformed material 503. FIG.5F shows an example of a third fraction of transformed material 507within the heated tile 506, and the previously formed tiles oftransformed material (503 and 505). FIG. 5G shows an example of thepreviously formed tiles 503, 505, and 507 disposed on the target surface501, which tiles are not arranged on a straight line. As a comparativeexample, FIGS. 5H and 5I show examples of alternative continuation stepsto the process shown in FIGS. 5A-5C, in which the heated tiles (e.g.,patches) and/or fractions of transformed material are deposited in astraight-line configuration. FIG. 5I shows an example of threetransformed material tiles 503, 509, and 511 disposed in a straight-lineconfiguration. Such straight-line configuration may form a line ofweakness, for example, that propagates through fractions 503, 509, and511, or propagates adjacent to fractions 503, 509, and 511. In anotherversion of the pointillism process, the tiles or transformed materialare formed without pre-heating the tile area.

In some instances, the methods, systems and/or apparatuses may comprisesensing (e.g., measuring) the temperature and/or the shape of thetransformed (e.g., molten) fraction within the heated tile. Thetemperature measurement may comprise real time temperature measurement(e.g., during the formation of the 3D object, during the formation of alayer of the 3D object, or during the formation of the tile). The FLS(e.g., depth) of the transformed fraction may be estimated (e.g., basedon the temperature measurements). The temperature measurements and/orestimation of the FLS of the transformed fraction (e.g., depth) may beused to control (e.g., regulate and/or direct) at least onecharacteristics of the energy irradiated at a particular portion. The atleast one characteristics may comprise the power, dwell time, crosssection, or footprint of the energy irradiated on the target surface.The control may comprise reducing (e.g., halting) the irradiated energyflux on reaching a target depth. The dwell time (e.g., exposure time)may be at least a few tenths of millisecond (e.g., from about 0.1), orat least a few milliseconds (e.g., from about 1 msec). The exposure time(e.g., dwell time) may be any dwell time disclosed herein. The controlmay comprise reducing (e.g., halting) the irradiated energy whileconsidering the rate at which the heated portions cool down. The ratemay depend on the ambient temperature (e.g., environmental temperature).The rate of heating and/or cooling the portions may facilitate formationof a desired microstructure (e.g., in particular areas). The desiredmicrostructures may be formed in an area within the layer of hardenedmaterial, or in (e.g., substantially) the entire layer of hardenedmaterial. The temperature at the heated (e.g., heat tiled) area may bemeasured. The temperature measurements may comprise spectroscopy,visually, or using expansion properties of a known material (e.g.,thermocouple or thermometer). The visual measurement may comprise usinga camera (e.g., CCD camera, or video camera) or a spectrometer. Thevisual measurements may comprise using image processing. Thetransformation of the heated tile may be monitored (e.g., visuallyand/or electronically). The overall shape of the transforming fractionof the tile may be monitored (e.g., visually and/or in real-time). TheFLS of the transformed(ing) fraction may be used to indicate the depthand/or volume of the transformed material (e.g., melt pool). Themonitoring (e.g., of the heat and/or FLS of the transformed fractionwithin the tile) may be used to control one or more parameters (e.g.,characteristics) of the tiling energy source, tiling energy flux,scanning energy source, and/or scanning energy beam. The parameters maycomprise (i) power density, (ii) dwell time, (iii) travel speed, or (iv)cross section. The parameters may be during heating to a temperaturebelow the transformation temperature, or during transformation of thematerial to form a tile of transformed material.

In some embodiments, the tiling energy flux is used, at least in part,to form at least the bottom skin layer. For example, the tiling energyflux is used to form at least the first 20, 25, 30, 35, or 40 layers ofhardened material, or all the layers of hardened material in the 3Dobject. A subsequent layer of hardened material (e.g., second layer) isa layer that is formed on (e.g., directly on) a previously formed layerof hardened material as part of the 3D object. The tiling energy fluxmay be used at least in part to form the second layer of hardenedmaterial of the 3D object and/or any subsequent layer of hardenedmaterial of the 3D object. In some instances, a layer of pre-transformed(e.g., powder) material is dispensed above (e.g., on) a layer ofhardened material (that is a part of the 3D object).

In some embodiments, the tiling energy flux forms a second layer ofhardened material by transforming (e.g., melting) at least a portion ofthe newly dispensed layer of pre-transformed material. The tiling energyflux may heat (e.g., and transform) a portion of the newly depositedlayer of pre-transformed material and a portion of at least onepreviously formed layer (or layers) of hardened material that isdisposed beneath the newly dispensed layer of pre-transformed material.The tiling energy flux may transform a portion of at least one newlydeposited layer of pre-transformed material and a portion of at leastone previously formed layers of hardened material that is disposedbeneath the newly dispensed layer of pre-transformed material. Thepreviously formed layers may or may not comprise the bottom skin layer.The tiling energy flux may heat (e.g., transform) tiles by transforminga portion of the pre-transformed material in the material bed, bytransforming (e.g., melting) a portion of the hardened material withinat least one previously formed layer of hardened material. For example,by transforming (e.g., melting) a portion of the hardened materialwithin a multiplicity of previously formed layer of hardened material.For example, the tiling energy flux may transform a portion of thehardened material that is disposed in the bottom skin layer of hardenedmaterial of the 3D object. Melting can be complete melting of thematerial (e.g., to a liquid state).

The first layer of hardened material may comprise fully dense hardenedmaterial. The first layer of hardened material may comprise hardenedmaterial that is not fully dense (e.g., that is porous). For example,the first layer of hardened material may comprise holes (e.g., pores).The tiling energy flux may be utilized to reduce the FLS of the holes.The tiling energy flux may be utilized to substantially reduce thenumber, FLS, and/or volume of the holes (e.g., eliminate the holes). Thetiling energy flux may be used to cure the layer of hardened material toprovide a (e.g., substantially) high density layer of hardened material.For example, a fully dense layer of hardened material. The externalsurface of the layer of hardened material (e.g., external surface of the3D object) may comprise a pattern of the tiles. For example, the patternmay resemble a checkerboard pattern. The tiling energy flux may alterthe microstructure within the tile (e.g., by heating and/or transformingat least a portion of the 3D object).

In some instances, it is desired to have a 3D object (or portionthereof) that has a certain amount of porosity. The hardened materialmay have a porosity of at most about 0.05 percent (%), 0.1% 0.2%, 0.3%,0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%,10%, 20%, 30%, 40%, 50%, 60%, 70%, or 80%. The hardened material mayhave a porosity of at least about 0.05 percent (%), 0.1%, 0.2%, 0.3%,0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%,10%, 20%, 30%, 40%, 50%, 60%, 70%, or 80%. The hardened material mayhave a porosity between any of the afore-mentioned porosity percentages(e.g., from about 0.05% to about 0.2%, from about 0.05% to about 0.5%,from about 0.05% to about 20%, from about from about 0.05% to about 50%,or from about 30% to about 80%). In some instances, a pore maytransverse the formed 3D object. For example, the pore may start at aface of the 3D object and end at the opposing face (e.g., bottom skin)of the 3D object. The pore may comprise a passageway extending from oneface of the 3D object and ending on the opposing face of that 3D object(e.g., 3D plane). In some instances, the pore may not transverse theformed 3D object. The pore may form a cavity in the formed 3D object.The pore may form a cavity on a face of the formed 3D object (e.g., theface of the 3D plane). For example, pore may start on a face of the 3Dplane and not extend to the opposing face of that 3D plane.

The first layer of hardened material may be originally formed fromsuccessively deposited melt pools having a first average FLS. The tilingenergy flux that subsequently heats and/or transforms at least portionsof the first layer of hardened material, may cause an alteration of themicrostructure of the first layer of hardened material (e.g., alterationin melt pool FLS, melt pool orientation, material density distributionacross the melt pool, degree of compound segregation to grain (e.g.,melt pool) boundaries, degree of element segregation to grainboundaries, material phase, metallurgical phase, material porosity,crystal phase, crystal structure, or any combination thereof). Forexample, when the first layer of hardened material is originally formedfrom successively deposited melt pools having a first average FLS; thetiling energy flux (that subsequently heats and/or transforms at leastportions of the first layer of hardened material) may cause analteration of the microstructure of that first layer such that the newlyformed melt pools in this first layer are larger than the first averageFLS (e.g., original melt pool FLS). Larger may be larger by at least1.5*, 2*, 3*, 5*, 10*, 20*, or 50* from the first average FLS of themelt pools. In some instances, the first layer will substantiallycomprise a single melt pool after subsequent heating by the tilingenergy flux. The 3D object may be a 3D plane or a wire.

The subsequent layers of hardened material may be formed by using thetiling energy flux, the energy beam, or any combination thereof. In someexamples, the bulk areas that form the layer of hardened material areformed using the tiling energy flux (e.g., larger cross section energyflux), and the fine features are formed using the energy beam (e.g.,smaller cross section energy beam). The energy beam and/or flux may befocused or defocused.

The hardened material may be substantially planar (e.g., flat), or maybe curved after its formation and/or heating by the tiling energy flux.The curvature may be positive or negative. The curvature may be anyvalue of curvature and/or radius of curvature disclosed herein. Thecurvature may be of the layer of hardened material or of a portionthereof (e.g., of a single tile). Heating a layer of hardened materialwith the tiling energy flux may introduce curvature to that layer (or toa portion thereof). The manner of heating a layer of hardened material(or a portion thereof) with the irradiated energy may influence thedegree and/or direction of the curvature. The manner of heating a layerof hardened material (or a portion thereof) with the irradiated energymay influence the stress at the top surface of the layer of hardenedmaterial (or the portion thereof). The manner of heating a layer ofhardened material (or a portion thereof) may comprise controlling and/oraltering the height of the powder layer, the density of the powderlayer, the dwell time of the irradiated energy, the power density of theirradiated energy, the temperature of the material bed (e.g., or theexposed surface thereof), the temperature of the layer of hardenedmaterial, the temperature of the bottom skin layer, or any combinationthereof. The control may depend on the temperature at the area that isheated (e.g., tiled), or an area at the vicinity of the heated area, orat the bottom skin layer. In some exhales, the vicinity is at most about2, 3, 4, 5, 6, 7, or 10 melt pool FLS (e.g., diameters) away from themelt pool center. The control may depend on a FLS of the melt pool. Theirradiated energy may comprise the tiling energy flux or the scanningenergy beam.

In some instances, a layer of pre-transformed material may have asubstantially fixed height. At times, the tiling energy flux and/or theenergy beam may transform several substantially fixed height layers ofpre-transformed material at once. At times, several layers ofpre-transformed material of a substantially fixed height may bedeposited sequentially in a material bed, followed by an energyirradiation that transforms a portion of the multiplicity of layers ofpowder material in one scanning of the irradiated energy. In thismanner, several layers of pre-transformed material may be transformedtogether (referred to herein as “deep transformation”). The deeptransforming can comprise deep melting (e.g., deep welding). Deeptransformation may comprise deep tiling. The multiplicity ofpre-transformed material layers may be of a single type of material, orof different types of material.

FIG. 35A shows an example of deep transformation. The irradiated energy3501 may transform a portion of a material bed (e.g., formed of layersof pre-transformed material 3503) to form a melt pool 3502, which meltpool spans several layers of pre-transformed material. In the exampleshown in FIG. 35B, the layers of pre-transformed material are disposedabove a platform 3504. In the example shown in FIG. 35A, the layers ofpre-transformed material are disposed above a platform 3514.

FIG. 35B shows an example of shallow transformation. In someembodiments, a multiplicity of layers of pre-transformed material issequentially deposited, and the top layer (or optionally at least 2, or3 top layers) is transformed, wherein the bottom layers remain loose(i.e., uncompact) and flowable (e.g., flowable powder material). Thisprocess is referred to herein as “shallow transformation.” Shallowtransformation may comprise shallow melting. FIG. 35B shows an exampleof shallow transformation. The irradiated energy 3511 may transform aportion of a material bed (e.g., formed of layers of pre-transformedmaterial (e.g., 3513)) to form a melt pool 3512, which melt pool isconfined in the uppermost layer of pre-transformed material (e.g.,3513). Shallow tiling excludes plastically deforming the bottom skinlayer, while deep tiling includes at least reaching an elevatedtemperature that is above the solidus temperature, transforming (e.g.,melting), becoming liquidus, and/or plastically yielding (e.g.,deforming) the bottom skin layer. In some embodiments, deep tiling alsoincludes transforming the bottom skin layer.

The shallow transformation may be effectuated by a shorter dwell times,and/or lower power density of the irradiated energy (e.g., shorterexposure times). The exposure time during the shallow transformation maybe at least about 0.1 milliseconds (msec), 0.5 msec, 1 msec, 3 msec, 5msec, 10 msec, 20 msec, 30 msec, 40 msec, or 50 msec. The exposure timeduring the shallow transformation may be at most about 3 msec, 5 msec,10 msec, 20 msec, 30 msec, 40 msec, or 50 msec. The exposure time may bebetween any of the above-mentioned exposure times (e.g., from about 0.1msec to about 50 msec, from about 0.1 to about 1 msec, from about 1 msecto about 10 msec, from about 10 msec to about 10 msec, from about 1 msecto about 1 msec, or from about 1 msec to about 20 msec).

The deep transformation may be effectuated by longer dwell times, and/orhigher power density of the tiling energy flux and/or scanning energybeam (e.g., shorter exposure times). The exposure time during the deeptransformation may be at least about 50 msec, 60 msec, 70 msec, 80 msec,90 msec, 100 msec, 200 msec, 400 msec, 500 msec, 1000 msec, 2500 msec,or 5000 msec. The exposure time during the deep transformation may be atmost about 60 msec, 70 msec, 80 msec, 90 msec, 100 msec, 200 msec, 400msec, 500 msec, 1000 msec, 2500 msec, or 5000 msec. The exposure timemay be between any of the above-mentioned exposure times (e.g., fromabout 50 msec to about 5000 msec, from about 100 msec to about 200 msec,from about 50 msec to about 400 msec, from about 100 msec to about 1000msec, or from about 1000 msec to about 5000 msec).

The manner of heating the one or more layers of pre-transformed material(or a portion thereof) may comprise controlling and/or altering theheight of the pre-transformed material layer, the density of thepre-transformed material layer, the dwell time of the irradiated energy,the power density of the irradiated energy, the temperature of thematerial bed, or any combination thereof. The temperature of thematerial bed may comprise the temperature of the exposed surface of thematerial bed, bottom of the material bed (e.g., at the platform),average material bed temperature, middle material bed temperature, orany combination thereof. The control may depend on the temperature atthe area of the material bed that is heated (e.g., tiled), or an area atthe vicinity of the heated area. Vicinity may be at most about 2, 3, 4,5, 6, 7, 8, 9, or 10 times the FLS of the tile.

The control of the irradiating energy (e.g., beam and/or flux) maycomprise substantially ceasing (e.g., stopping) to irradiate the targetarea when the temperature at the bottom skin reached a targettemperature. The target temperature may comprise a temperature at whichthe material (e.g., pre-transformed or hardened) reaches an elevatedtemperature that is above the solidus temperature, transforms (e.g.,re-transforms, e.g., re-melts), become liquidus, and/or plasticallyyields. The control of the irradiating energy may comprise substantiallyreducing the energy supplied to (e.g., injected into) the target areawhen the temperature at the bottom skin reached a target temperature.The control of the irradiated energy may comprise altering the energyprofile of the energy beam and/or flux respectively. The control may bedifferent (e.g., may vary) for layers that are closer to the bottom skinlayer as compared to layers that are more distant from the bottom skinlayer (e.g., beyond the critical layer thickness as disclosed herein).The control may comprise turning the irradiated energy on and off. Thecontrol may comprise reducing the power per unit area, cross section,focus, power, of irradiated energy. The control may comprise altering atleast one property of the irradiated energy, which property may comprisethe power, power per unit area, cross section, energy profile, focus,scanning speed, pulse frequency (when applicable), or dwell time of theirradiated energy. During the “off” times (e.g., intermission), thepower and/or power per unit area of the energy beam and/or flux may besubstantially reduced as compared to its value at the “on” times (e.g.,dwell times). Substantially may be in relation to the transformation ofthe material at the target surface. During the intermission, theirradiated energy may relocate away from the area which was tiled, to adifferent area in the material bed that is substantially distant fromarea which was tiled (see examples 1). During the dwell times, theirradiated energy may relocate back to the position adjacent to the areawhich was just tiled (e.g., as part of the path-of-tiles).

As understood herein: The solidus temperature of the material is atemperature wherein the material is in a solid state at a givenpressure. The liquefying temperature of the material is the temperatureat which at least part of the pre-transformed material transitions froma solid to a liquid phase at a given pressure. The liquefyingtemperature is equal to a liquidus temperature where the entire materialis in a liquid state at a given pressure.

FIG. 37 shows an example of a top view of a target surface. The path oftiles in the example of FIG. 37 includes tiles 3702, 3704, and3706-3711. The first tile formed by the irradiated energy is 3702 duringa first dwell time, during the first intermission, the irradiated energyrelocated to position 3703; during the second dwell time, the irradiatedenergy relocated back to the path-of-tiles and formed tile 3704; duringthe second intermission, the irradiated energy relocated to position3705; during the third dwell time, the irradiated energy relocates backto the path-of-tiles and formed tile 3706. During the intermission, theirradiated energy may be heat and/or transform the material bed at therelocated position (e.g., 3703) that is distant from the path-of-tiles.The irradiated energy may form two distant paths-of-tiles by using theintermission time during the formation of the first path-of-tiles, toform the second path-of-tiles. The intermission of the first path oftiles can be a dwell time of the irradiated energy in the second path oftiles.

At times, hardened material may protrude from the exposed surface of thepowder bed. FIG. 38 shows an example of a hardened material 3800 withinthe material bed 3810 that is located above a platform 3811. Thematerial bed 3810 includes an exposed surface 3812. The hardenedmaterial 3800 protrudes from the exposed surface 3812 at a location3814. The area of protrusion (e.g., horizontal cross section thereof)may be masked from the irradiated energy. In some instances, theirradiated energy may not irradiate the area (e.g., horizontal crosssection thereof) which comprises the protruding hardened material. Insome instances, the irradiated energy may irradiate the exposed surfaceof the material bed that is free of protruding objects (e.g., does notcomprise protruding objects). In some instances, the irradiated energymay not irradiate the area which comprises the protruding object, andirradiate the exposed surface of the material bed that is free ofprotruding objects. The path in which the irradiated energy travels mayexclude areas of protruding hardened material. The exclusion of theprotrusion areas can be done before the irradiated energy transformsportions in a layer of pre-transformed material. The exclusion of theprotrusion areas can be done in-real time (e.g., while the irradiatedenergy transforms portions in a layer of pre-transformed material(referred to herein as “dynamic path adjustment”)) The path of theenergy beam and/or flux can be adjusted dynamically as the irradiatedenergy travels along the exposed surface of the material bed. Theadjustment of the path may consider a (e.g., optical) detection of theprotruding object. For example, a real time (e.g., and in situ) opticaldetection as disclosed in U.S. Provisional Patent Application Ser. No.62/297,067 that was filed on Feb. 18, 2016, and U.S. Provisional PatentApplication Ser. No. 62/401,534 that was file on Sep. 29, 2016, both ofwhich are incorporated herein by reference in their entirety.

The tiling of the target surface may follow a step and repeat sequence.The tiling of the target surface may follow a step and tile heatingprocess to a temperature below the transformation temperature of thematerial at the target surface. The tiling of the target surface mayfollow a step and tile transforming (e.g., “filling”) process. The“step” may designate the distance from a first tile to a second tile(e.g., the distance “d” shown in the example of target surface 310 inFIG. 3). The distance may be constant within a layer of hardenedmaterial. At times, the distance may vary within a layer. The “repeat”may designate the repeated heating (e.g., transforming) the targetsurface by a tiled area (e.g., tile 301 shown in the example of targetsurface 310 in FIG. 3).

The flash heating and/or deep tiling process may regulate thedeformation of at least one layer of hardened material. The flashheating and/or deep tiling process may reduce the magnitude ofdeformation of the at least one layer of hardened material. The flashheating and/or deep tiling process, in certain conditions, may increasethe deformation at least one layer of hardened material (e.g., in adesired direction). For example, the flash heating and/or deep tilingprocess may form at least one layer of hardened material that isnegatively warped (e.g., comprises a negative curvature, FIG. 17, 1712,layer number 6). Examples for methods forming a negatively warped objectcan be found in U.S. Provisional Patent Application Ser. No. 62/252,330,filed on Nov. 6, 2015; U.S. Provisional Patent Application Ser. No.62/396,584 filed on Sep. 19, 2016; and in PCT Patent Application SerialNo. PCT/US16/59781 filed on Oct. 31, 2016; all three of which are fullyincorporated herein by reference. The certain conditions may comprisethe geometry of the 3D object, the geometry of the at least one layer ofhardened material, the power of the irradiated energy, the dwell time ofthe irradiated energy (e.g., time to make a tile), or the speed of theirradiated energy (e.g., along the path).

The layer of hardened material may have a curvature. The curvature canbe positive or negative with respect to the platform and/or the exposedsurface of the material bed. FIG. 17 shows examples of a vertical crosssections in various layered structures. For example, layered structure1712 comprises layer number 6 that has a curvature that is negative, asthe volume (e.g., area in a vertical cross section of the volume) boundfrom the bottom of it to the platform 1718 is a convex object 1719.Layer number 5 of 1712 has a curvature that is negative. Layer number 6of 1712 has a curvature that is more negative (e.g., has a curvature ofgreater negative value) than layer number 5 of 1712. Layer number 4 of1712 has a curvature that is (e.g., substantially) zero. Layer number 6of 1714 has a curvature that is positive. Layer number 6 of 1712 has acurvature that is more negative than layer number 5 of 1712, layernumber 4 of 1712, and layer number 6 of 1714.

In some embodiments, the curvature of all the layers within the 3Dobject is from at most about 0.02 millimeters⁻¹ (i.e., 1/millimeters).In some embodiments, the layers within the 3D object are substantiallyplanar (e.g., flat). In some embodiments, all the layers of hardenedmaterial can have a curvature of at least about zero (i.e., asubstantially planar layer) to at most about 0.02 millimeters⁻¹. Thecurvature can be at most about −0.05 mm⁻¹, −0.04 mm⁻¹, −0.02 mm⁻¹, −0.01mm⁻¹, −0.005 mm⁻¹, −0.001 mm⁻¹, substantially zero mm⁻¹, 0.001 mm⁻¹,0.005 mm⁻¹, 0.01 mm⁻¹, 0.02 mm⁻¹, 0.04 mm⁻¹, or 0.05 mm⁻¹. The curvaturecan be any value between the afore-mentioned curvature values (e.g.,from about −0.05 mm⁻¹ to about 0.05 mm⁻¹, from about −0.02 mm⁻¹ to about0.005 mm⁻¹, from about −0.05 mm⁻¹ to substantially zero, or from aboutsubstantially zero to about 0.05 mm⁻¹). The curvature may refer to thecurvature of a surface. The surface can be of the layer of hardenedmaterial (e.g., first layer). The surface may be of the 3D object (orany layer thereof).

The radius of curvature, “r,” of a curve at a point is a measure of theradius of the circular arc (e.g., FIG. 17, 1716) which best approximatesthe curve at that point. The radius of curvature is the inverse of thecurvature. In the case of a 3D curve (also herein a “space curve”), theradius of curvature is the length of the curvature vector. The curvaturevector can comprise of a curvature (e.g., the inverse of the radius ofcurvature) having a particular direction. For example, the particulardirection can be the direction to the platform (e.g., designated hereinas negative curvature), or away from the platform (e.g., designatedherein as positive curvature). For example, the particular direction canbe the direction towards the direction of the gravitational field (e.g.,designated herein as negative curvature), or opposite to the directionof the gravitational field (e.g., designated herein as positivecurvature). A curve (also herein a “curved line”) can be an objectsimilar to a line that is not required to be straight. A line can be aspecial case of curve wherein the curvature is substantially zero. Aline of substantially zero curvature has a substantially infinite radiusof curvature. The curve may represent a cross section of a curved plane.A line may represent a cross section of a flat (e.g., planar) plane. Acurve can be in two dimensions (e.g., vertical cross section of aplane), or in three-dimension (e.g., curvature of a plane).

In some embodiments, cooling the tiles comprises introducing a coolingmember (e.g., heat sink) to the heated area. FIG. 1 shows an example ofa cooling member 113 that is disposed above the exposed (e.g., top)surface 119 of the material bed 104. The cooling member may betranslatable vertically, horizontally, or at an angle (e.g., planar orcompound). The translation may be controlled manually and/or by acontroller. The translation may be during the 3D printing. The coolingmember may be operatively coupled to the controller. The tiling energysource (e.g., FIG. 1, 114), first scanning energy source, secondscanning energy source, and/or cooling member may be translatablevertically, horizontally, or at an angle (e.g., planar or compound). Thetranslation may be controlled manually and/or by a controller. Thetranslation may be during at least a portion the 3D printing. In someembodiments, the energy sources are stationary. The tiling energysource, first scanning energy source, and/or second scanning energysource may be operatively coupled to the controller. The tiling energysource, first scanning energy source, second scanning energy source,and/or cooling member may be translated by a scanner. The cooling membermay control (e.g., prevent) accumulation of heat in certain portions ofthe exposed 3D object (e.g., exposed layer of hardened material).Heating a tile on the target surface in a particular area may control(e.g., regulate) accumulation of heat in certain portions of the exposed3D object (e.g., exposed layer of hardened material).

The flash heating, deep tiling, and/or shallow tiling method may furthercomprise preheating the material bed. Preheating the material bed maysubsequently require less power to transform at least a portion of theexposed surface of the target surface with the aid of the tiling energyflux and/or scanning energy beam (e.g., first and/or second). Preheatingand/or cooling the material bed may be from above, below, and/or sidesof the material bed. The cooling member may assist in maintaining thetemperature of the material bed and/or prevent transforming (e.g.,fusing or caking) the pre-transformed material within the material bedand/or (e.g., within any cavities of the 3D object).

The control may comprise a closed loop control, or an open loop control(e.g., based on energy calculations comprising an algorithm). The closedloop control may comprise feed-back or feed-forward control. Thealgorithm may consider one or more temperature measurements (e.g., asdisclosed herein), metrological measurements, geometry of at least partof the 3D object, heat depletion/conductance profile of at least part ofthe 3D object, or any combination thereof. The controller may modulatethe irradiative energy and/or the energy beam. The algorithm mayconsider pre-correction of an object (i.e., object pre-print correction,OPC) to compensate for any distortion of the final 3D object. Thealgorithm may comprise instructions to form a correctively deformedobject. The algorithm may comprise modification applied to the model ofa desired 3D object. Examples of modifications (e.g., correctivedeformations such as object pre-print correction) can be found in U.S.Provisional Patent Application Ser. No. 62/239,805, that was filed onOct. 9, 2015, and in PCT Patent Application Serial No. PCT/US16/34857that was filed on May 27, 2016, both of which are entirely incorporatedherein by reference. The control may be any control disclosed in U.S.Provisional Patent Application Ser. Nos. 62/297,067 and 62/401,534, bothof which are incorporated herein by reference in their entirety.

The methods for generating one or more 3D objects described herein maycomprise: depositing a layer of pre-transformed material (e.g., powder)in an enclosure; providing (e.g., irradiating) energy to a portion ofthe layer of material (e.g., according to a path); transforming at leasta section of the portion of the layer of pre-transformed material toform a transformed material by utilizing the energy; optionally allowingthe transformed material to harden into a hardened material; andoptionally repeating steps a) to d) to generate the one or more 3Dobjects. The enclosure may comprise a platform (e.g., a substrate and/orbase). The enclosure may comprise a container. The 3D object may beprinted adjacent to (e.g., above) the platform. The pre-transformedmaterial may be deposited in the enclosure by a material dispensingsystem to form a layer of pre-transformed material within the enclosure.The deposited material may be leveled by a leveling mechanism. Thedeposition of pre-transformed material in the enclosure may form amaterial bed. The leveling mechanism may comprise a leveling step wherethe leveling mechanism does not contact the exposed surface of thematerial bed. The material dispensing system may comprise one or moredispensers (e.g., FIG. 1, 116). The material dispensing system maycomprise at least one material (e.g., bulk) reservoir. The material maybe deposited by a layer dispensing mechanism (e.g., recoater). The layerdispensing mechanism may level the dispensed material without contactingthe powder bed (e.g., the top surface of the powder bed). The layerdispensing mechanism may include any layer dispensing mechanism (e.g.,FIG. 1, 116), material removal mechanism (e.g., 118), and/or levelingmechanism (e.g., 117) that are disclosed in Patent Application SerialNo. PCT/US15/36802 titled “APPARATUSES, SYSTEMS AND METHODS FOR 3DPRINTING” that was filed on Jun. 19, 2015 and that is incorporatedherein by reference in its entirety. The layer dispensing mechanism maycomprise a material dispensing mechanism, material leveling mechanism,material removal mechanism, or any combination thereof. In someembodiments, the pre-transformed material may be added and leveled bythe layer dispensing mechanism sequentially during the same run (e.g.,as it levels a layer of material in the material bed). For example,during one progression of the layer dispensing mechanism along thematerial bed, the layer dispenser may dispense material into (or toform) the material bed, which dispensed material is subsequently leveled(e.g., without contacting the top surface of the material bed), morematerial is dispensed (e.g., as the layer dispensing mechanism istranslating along the material bed), and the more material issubsequently leveled, etc. The layer dispensing mechanism can performone, two, or more material dispensing steps as it completes one lateralsweep of the material bed. The layer dispensing mechanism can performone, two, or more material leveling steps as it completes one lateralsweep of the material bed. The layer dispensing mechanism can performone, two, or more material removal steps as it completes one lateralsweep of the material bed. The layer dispensing mechanism can performone, two, or more material dispensing steps as it completes one lateralsweep of the material bed. The lateral sweep of the material bed can bea sweep of the material bed from one edge of the material bed to anopposite (e.g., laterally opposing) edge of the material bed.

FIG. 10A shows an example of a material bed 1012 comprising asubstantially planar exposed surface 1013 in which at least a portion ofa 3D object 1011 is formed by transforming a portion of the material bedusing an energy beam 1014, and subsequently forming a void 1016. Thelayer dispensing mechanism may comprise at least two of: a materialdispensing mechanism (e.g., dispenser), a leveling mechanism, and amaterial removal mechanism. FIG. 1 shows an example of a layerdispensing mechanism comprising a material dispensing mechanism 116, aleveling mechanism 117, and a material removal mechanism 118 (The whitearrows in 116 and 118 designate the direction in which thepre-transformed material flows into/out of the material bed 104). FIG.13 shows another example of a layer dispensing mechanism comprising amaterial dispensing mechanism 1305, a leveling mechanism (including 1306and 1304), and a material removal mechanism 1303, in which the threemechanism 1305, 1306 & 1304 and 1303 are connected (e.g., 1301 and1302). The layer removal mechanism and/or the layer dispensing mechanismmay comprise one or more nozzles. In the example of FIG. 13, 1312depicts an example of a nozzle comprising three openings 1314, 1315, and1316 through which material (e.g., pre-transformed material) may beattracted (e.g., pulled, or flow) into the nozzle (e.g., along arrows1317, 1318 and 1319). The flow of the material into the layer removingmechanism may comprise laminar flow. The flow of the material from thematerial bed into the layer removal mechanism may be in the upwardsdirection (e.g., against the gravitational center, and/or away from theplatform).

The layer dispensing mechanism may comprise a material (e.g., powder)removal mechanism (e.g., 1303) that comprises one or more openings. Theone or more openings may be included in a nozzle. The nozzle maycomprise an adjustable opening (e.g., regulated by a controller). Theheight of the nozzle opening relative to the exposed surface of thematerial bed may be adjustable (e.g., regulated by a controller). Thematerial removal mechanism may comprise a reservoir in which thematerial may at least temporarily accumulate. The evacuated material maycomprise a pre-transformed material that is evacuated by the materialremoval mechanism. The evacuated material may comprise a transformedmaterial that did not form the 3D object. FIG. 14 shows an example of amaterial removal mechanism comprising a nozzle 1404 through whichmaterial flows from the material bed 1407 into a reservoir 1403. In theexample in FIG. 14, the reservoir is connected to an attractive forcesource 1401 (such as a vacuum pump) through a channel (e.g., tube) 1402.At least one portion of the nozzle body may be adjustable. In someembodiments, at least one part of the nozzle body is adjustable at avertical, horizontal, or angular direction (e.g., with respect to theexposed surface of the material bed, and/or the building platform). Thenozzle may be formed of one or two thick portions (e.g., of which atleast one is movable). The thick section(s) may allow an internal volumeof the nozzle to be sealed (e.g., without forming a gap) by two opposingside walls that are disposed parallel to the movement axis of thematerial removal mechanism and span the maximum allowed movement of theat least one thick section (e.g., along 1405 and/or 1406). The materialremoval mechanism (e.g., comprising the nozzle and the internalreservoir) may translate vertically, horizontally, and/or at an angle(e.g., along 1409). The translation may be before, after, and/or duringat least a portion of the 3D printing (e.g., to planarize the exposedsurface of the material bed). In the example of FIG. 14, one or twoparts of the nozzle body are adjustable at a vertical, horizontal, orangular direction (e.g., with respect to the exposed surface of thematerial bed, and/or the building platform) as indicated by arrows 1405and 1406. The nozzle may comprise an adjustable opening (e.g.,controlled by a controller). The height of the nozzle opening relativeto the exposed surface of the material bed may be adjustable (e.g.,controlled by a controller). The material removal mechanism may comprisea reservoir in which the material (that is evacuated by the materialremoval mechanism) may at least temporarily accumulate. Control mayinclude regulate and/or direct.

The FLS of the opening (e.g., cross section thereof) of the materialremoval mechanism (e.g., nozzle diameter) may be at least about 0.1 mm,0.4 mm, 0.7 mm, 0.9 mm, 1.1 mm, 1.3 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5mm, 5 mm, 7 mm, or 10 mm. The FLS of the opening of the material removalmechanism (e.g., nozzle diameter) may be at most about 0.1 mm, 0.4 mm,0.7 mm, 0.9 mm, 1.1 mm, 1.3 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 5mm, 7 mm, or 10 mm. The FLS of the opening of the material removalmechanism (e.g., nozzle diameter) may be of any value between theafore-mentioned values (e.g., from about 0.1 mm to about 7 mm, fromabout 0.1 mm to about 0.6 mm, from about 0.6 mm to about 0.9 mm, fromabout 0.9 mm to about 3 mm, or from about 3 mm to about 10 mm).

The nozzle may comprise a material entrance opening through whichmaterial enters from the material bed (e.g., 1408) into the nozzle(e.g., along arrow 1404). The nozzle can be a Venturi nozzle. Theopening may comprise a narrow portion (e.g., a “bottle neck”).Sometimes, the narrow portion is at the entrance of the nozzle (e.g.,FIG. 15, 1520). At times, the narrow portion is away from the opening(e.g., FIG. 14, 1408, the narrow opening is designated by “d1”). Attime, the FLS (e.g., diameter) of the opening is larger than the FLS ofthe narrow portion within the nozzle. At time the FLS of the opening isthe narrows portion of the nozzle. The FLS of the narrow portion may beconstant or variable. The FLS of the narrow portion may be variedmechanically, electronically, thermally, hydraulically, magnetically, orany combination thereof.

The nozzle may be symmetric or asymmetric. A vertical and/or horizontalcross section of the nozzle may be asymmetric. For example, a verticalcross section of the nozzle interior may reveal its asymmetry. Theasymmetry can be in the materials from which the nozzle is composed. Theasymmetry can be manifested by a lack of at least one symmetry axis. Forexample, a lack of n fold rotational axis (e.g., lack of C_(n) symmetryaxis, wherein n equals at least 2, 3, or 4). For example, a lack of atleast one symmetry plane. For example, a lack of inversion symmetry. Insome embodiments, the nozzle comprises a symmetry plane, but lackrotational symmetry. In some embodiments, the nozzle lacks both arotational symmetry axis, and a symmetry plane. The axis of symmetry maybe substantially perpendicular to the average surface of the exposedsurface of the material bed, to the building platform, or to a planenormal to the direction of the gravitational force. The axis of symmetrymay be at an angle between 0 degrees and 90 degrees relative to theaverage surface of the exposed surface of the material bed, to thebuilding platform, to a plane normal to the direction of thegravitational force, to any combination thereof. The nozzle may have abent shape. The nozzle can have a crooked shape. The bent shape mayfollow a function. The function may be exponential or logarithmic. Thefunction may be a portion of a circle or a parabola. The bent shape canroughly resemble the letter “L” or “J.” The bent shape can be a smoothlybent shape. The bent shape can be a curved shape. FIG. 15 shows anexample of vertical cross section of various nozzles 1501, 1503, 1505,1511, 1513, and 1415. In some examples, material flows into or out ofthe nozzles. Arrows 1502, 1504, 1506, 1512, 1514, and 1516 show anexample of the direction in which material flows from the material bed(e.g., 1507 or 1517 respectively) into the appropriate nozzles. Nozzles1505 and 1515 show examples of symmetrical cross sections of nozzles,with a mirror axis of symmetry along the arrows 1506 and 1516respectively. Nozzles 1503, 1501, show examples of non-symmetrical crosssections of nozzles as this cross section lacks an axis of symmetry. Thenozzle may be a long nozzle (e.g., vacuum nozzle) in the horizontaland/or vertical direction. The nozzle may be symmetric or asymmetric.The symmetry axis may be in a horizontal and/or vertical cross-sectionof the nozzle. FIG. 15 shows examples of nozzles depicted as verticalcross sections. Nozzle 1503 shows an example of a nozzle that is long inthe vertical direction. The axis of symmetry for nozzle 1515 can bealong the arrow 1516. The nozzle may be a vacuum nozzle. The nozzle maycomprise laminar or turbulent flow during its operation (e.g., suction).The magnitude of laminar flow between two sides of the nozzle (e.g., twovertical sides of the nozzle) can be the same or different. Themagnitude of laminar flow between two sides of the asymmetric nozzle(e.g., the two asymmetric vertical sides of the nozzle) can be the sameor different. The gas flow within the nozzle (e.g., during itsoperation) may comprise laminar flow. The gas flow within the nozzle(e.g., during its operation) may comprise turbulence. The gas flowbetween the exposed surface and the nozzle entrance (e.g., during itsoperation) may comprise laminar flow. The gas flow between the exposedsurface and the nozzle entrance (e.g., during its operation) maycomprise turbulence. The turbulence may be a desired turbulence. Theflow rate of the gas within the nozzle (e.g., suction power) may dependon the size and/or mass of the particulate material (e.g., particlesforming the powder bed).

In some embodiments, the pre-transformed material (e.g., powder) isattracted utilizing the force source to the opening port of the materialremoval mechanism and flows above the material bed in a substantiallyhorizontal flow. FIG. 33 shows an example of a material removalmechanism, and illustrates a horizontal flow S1 of the pre-transformedmaterial toward the opening port 3300. The substantially horizontal flowof the pre-transformed material above the material bed may be relativeto the position of the material bed (e.g., relative speed). The relativespeed (e.g., velocity) of substantially horizontal flow towards theopening port of the material removal member may be at least 0.5 meterper second (m/sec), 1 m/sec, 2 m/sec, 3 m/sec, 4 m/sec, 5 m/sec, 6m/sec, 7 m/sec, 8 m/sec, 9 m/sec, 10 m/sec, 20 m/sec, 30 m/sec, 40m/sec, or 50 m/sec. The relative speed of substantially horizontal flowtowards the opening port of the material removal member may be any speedbetween the afore-mentioned speed values (e.g., from about 0.5 m/sec toabout 50 m/sec, from about 1.5 m/sec to about 3 m/sec, from about 3m/sec to about 6 m/sec, from about 6 m/sec to about 10 m/sec, or fromabout 10 m/sec to about 50 m/sec).

In some embodiments, the particulate material (e.g., powder) isattracted to the opening port of the material removal mechanism andflows toward a position above the material bed in a substantiallyvertical flow. FIG. 33 shows an example of a material removal mechanism,and illustrates a vertical flow S2 of the pre-transformed materialtoward the opening port 3300. The speed of substantially vertical flowtowards the opening port of the material removal member may be at least30 meter per second (m/sec), 40 m/sec, 50 m/sec, 60 m/sec, 70 m/sec, 80m/sec, 90 m/sec, 100 m/sec, 200 m/sec, 300 m/sec, 400 m/sec, 500 m/sec,600 m/sec, or 700 m/sec. The speed of substantially vertical flowtowards the opening port of the material removal member may be any speedbetween the afore-mentioned speed values (e.g., from about 30 m/sec toabout 700 m/sec, from about 30 m/sec to about 60 m/sec, from about 60m/sec to about 500 m/sec, from about 60 m/sec to about 100 m/sec, orfrom about 100 m/sec to about 700 m/sec).

In some embodiments, the speed of the vertical flow is greater than thespeed of the horizontal flow. The speed of the vertical flow may begreater by at least about 1.5*, 2*, 2.5*, 3*, 4*, 5*, 6*, or 10*(i.e.,times) the speed of the horizontal flow. The speed of the vertical flowmay any value between the afore-mentioned values (e.g., from about 1.5*to about 10*, from about 1.5* to about 2.5*, from about 2.5* to about5*, or from about 5* to about 10* (i.e., times) the speed of thehorizontal flow).

The (e.g., laminar) flow of pre-transformed (e.g., powder) material intothe (e.g., vacuum) nozzle may create an area of low pressure, which mayin turn generate a vertical force which would result in a horizontalforce acting on the pre-transformed (e.g., particulate) material (e.g.,at the exposed surface of the material bed). Due to the operation of thenozzle, the pre-transformed material in the material bed (e.g., exposedsurface thereof) may be subject to the Bernouli principle.

In some embodiments, the nozzle is separated from the exposed surface ofthe material bed by a gap (e.g., vertical distance, FIG. 33, 3312). Thegap may comprise a gas. The gas may be an atmospheric gap. The extent ofthe gap and/or the FLS of the opening port (e.g., diameter) of thenozzle may be changeable (e.g., before, after, and/or during the 3Dprinting). For example, that change in the nozzle opening port may occurduring the operation of the material removal mechanism. For example,that change may occur before the initiation of the 3D printing. Forexample, that change may occur during the formation of the 3D object.For example, that change may occur during the formation of a layer ofhardened material. For example, that change may occur after transforminga portion of a layer of pre-transformed (e.g., powder) material. Forexample, that change may occur before deposition a subsequent layer ofpre-transformed material. For example, that change may occur during theprogression of the layer dispensing mechanism (e.g., of which thematerial removal mechanism is a part of) along the exposed surface ofthe material bed. The progression may be parallel to the exposes surfaceof the material bed. The progression may be a lateral progression (e.g.,from one side of the material bed to the opposite side of the materialbed). In some embodiments, the extent of the gap and/or the FLS of theopening port (e.g., diameter) of the nozzle may be unchanged before,after, and/or during the formation of: the 3D object, layer of hardenedmaterial, transformed material, or any combination thereof. The extentof the gap and/or the FLS of the opening port (e.g., diameter) of thenozzle may be unchanged during the formation of: the 3D object, layer ofhardened material, transformed material, or any combination thereof. Thevertical distance of the gap from the exposed surface of the targetsurface to the entrance opening of the nozzle (e.g., 3312) may be atleast about 0.05 mm, 0.1 mm, 0.25 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm. The vertical distance of the gapfrom the exposed surface of the powder bed may be at most about 0.05 mm,0.1 mm, 0.25 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm,9 mm, 10 mm, or 20 mm. The vertical distance of the gap from the exposedsurface of the powder bed may be any value between the afore-mentionedvalues (e.g., from about 0.05 mm to about 20 mm, from about 0.05 mm toabout 0.5 mm, from about 0.2 mm to about 3 mm, from about 0.1 mm toabout 10 mm, or from about 3 mm to about 20 mm).

The velocity (e.g., speed) of the material removal mechanism may bealtered. The velocity by which a pre-transformed (e.g., powder) materialis removed from the material bed by the material removal system may bealtered. The force exerted by the material removal mechanism (e.g.,through the nozzle) on the pre-transformed material (e.g., powder)disposed in the material bed, may be altered. The alteration may bebefore, after, and/or during the formation of: the 3D object, layer ofhardened material, transformed material, or any combination thereof. Thealteration may be during the formation of the 3D object, layer ofhardened material, transformed material, or any combination thereof.

FIGS. 28A-C and 29A-E schematically depict bottom views of variousmechanisms for removing the pre-transformed material as part of thematerial removal mechanism. FIG. 28A schematically depicts a bottom viewof a material removal mechanism 2811 having an elongated materialentrance opening port 2812, which material removal mechanism isconnected 2815 to channel 2814 through which the pre-transformedmaterial leaves the material removal mechanism. FIG. 28B schematicallydepicts a bottom view of a material removal member having manifolds(e.g., 2823) of multiple pre-transformed material (e.g., powder)entrance opening ports (e.g., 2822). FIG. 28C schematically depicts anintegrated material dispensing-removal member having material entranceopening ports (e.g., 2832), and material exit opening ports (e.g.,2833). Other examples of material removal mechanisms can be found inPatent Application Serial No. PCT/US15/36802 which is fully incorporatedherein by reference in its entirety.

FIG. 29A schematically depicts a bottom view of a material removalmechanism having an elongated material entrance opening port 2912 and aninternal compartment having a triangular horizontal cross section 2911.FIG. 29B schematically depicts a bottom view of a material removalmember having a multiplicity of pre-transformed material entranceopening ports (e.g., 2922) and an internal compartment having anegg-like cross section 2921. FIG. 29C schematically depicts a bottomview of a material removal member having multiple pre-transformedmaterial (e.g., powder) entrance opening ports (e.g., 2932) and aninternal compartment having a trapezoid horizontal cross section 2931.FIG. 29D schematically depicts a bottom view of a material removalmember having a pre-transformed material entrance opening port (2942)and an internal compartment having cross section 2941 of a narrowinghelix (e.g., narrowing screw). In some embodiments, the cross section isa horizontal cross section. In some examples, the horizontal crosssection spans (e.g., approximately) the width or length of the targetsurface (e.g., FIG. 27). In some examples, the horizontal cross sectionis less than (e.g., approximately) the width or length of the targetsurface. In some examples, the horizontal cross section exceeds (e.g.,approximately) the width or length of the target surface. FIG. 29Eschematically depicts a bottom view of a material removal member havinga pre-transformed material entrance opening port (2952) and an internalcompartment having a horizontal cross section 2941 of a tubular helix(e.g., Archimedean screw).

The nozzle may be a long nozzle (e.g., vacuum nozzle) in the horizontaldirection. The long nozzle may be referred herein as an elongatednozzle. FIG. 28A shows an example of an elongated nozzle in thehorizontal direction, having a horizontally elongated material entryport 2812. In some examples, the nozzle spans at least a portion of thewidth or length of the material bed. In some examples, the nozzle spansless than the width or length of the material bed. FIG. 27 showsexamples of a width and a length. The nozzle may span approximately thewidth or length of the material bed. The nozzle may be symmetric orasymmetric. The symmetry axis may be horizontal and/or vertical (e.g.,substantially parallel to the platform).

A cross section of the material removal member opening port (e.g.,nozzle entrance) may be rectangular (e.g., 2912, 2932), or elliptical(e.g., 2922). The rectangular opening may be a square. The ellipticalopening may be a circle (e.g., 2832). A cross section of the materialremoval member opening port (e.g., nozzle entrance) may comprise acurvature (e.g., curved edge) or a straight line (e.g., straight edge).The FLS (e.g., width to length) of the opening port cross section mayhave an aspect ratio of at least 1:2, 1:10, 1:100, 1:1000, 1:1000, or1:10000.

The material removal member may comprise a connector. The connector maybe to a power source (herein referred to as “power source connector”).The connector may be to a reservoir. The connector may be both to areservoir and to the power source connection. FIG. 28B shows an exampleof a connector 2825. The power source may be a source of gas flow (e.g.,compressed gas, or vacuum), electrostatic force, and/or magnetic force.The connector may allow a fluid connection (e.g., such that thepre-transformed material may flow through). FIG. 28C show an example ofa fluid connection 2834 (e.g., to the power source). The connector mayallow pre-transformed and/or small bits of transformed material to flowthrough (e.g., FIG. 28B, 2824). The connector may allow gas to flowthrough. The connector may comprise connection to a channel (e.g., FIG.28A, 2814). The channel (e.g., tube) may be flexible or non-flexible.Examples of connectors are shown in 2815, 2825, 2835, 2915, 2925, 2935,2945, and 2955. Examples of channels are shown in 2814, 2824, 2834,2914, 2924, 2934, 2944, and 2954.

In some examples, the material removal member comprises an internalcompartment. The internal compartment may be a pre-transformed materialcollection compartment. For example, the internal compartment may be apowder collection compartment, or a liquid collection compartment. Theinternal compartment may connect (e.g., fluidly connect) to the powersource (e.g., through the connector and the channel). The internalcompartment may comprise the connector. FIG. 28A shows an example of aconnector 2815. The internal compartment may connect (e.g., fluidly) tothe one or more nozzles. The internal compartment may connect (e.g.,fluidly) to the one or more nozzles and to the power source and/orreservoir. The internal compartment may be symmetric or asymmetric. Thesymmetry or asymmetry may be in the horizontal and/or verticaldirection. The internal compartment may comprise the shape of acylinder, cone, box, ellipsoid, egg, or a spiral. The cross section(e.g., horizontal and/or vertical) may comprise the shape of a triangle(e.g., 2911), ellipse, rectangle (e.g., 2811), parallelogram, trapezoid(e.g., 2931), egg cross section (e.g., 2921), spiral cross section(e.g., 2941 or 2951), star, sickle, or crescent. The cross section(e.g., horizontal and/or vertical) may comprise a concave shape or aconvex shape. FIG. 28B shows an example of an internal compartmenthaving a cross section of a rectangle 2821. The long axis of theinternal compartment may be substantially parallel to the platform. Ashort axis of the internal compartment may be substantiallyperpendicular to the platform. The internal compartment may comprise acurvature. The internal compartment may comprise a curved plane. Theinternal compartment may comprise a planar (e.g., non-curved, or flat)plane. A horizontal cross section of the internal compartment may besymmetric (e.g., a rectangle) or asymmetric (e.g., a triangle). Theinternal compartment may be wider (e.g., 2916) towards the connector(e.g., 2915). The internal compartment may be narrower (e.g., 2913) awayfrom the connector. The shape of the internal compartment may allowsubstantial uniform removal (e.g., suction) of the pre-transformedmaterial by the nozzle(s) of the material removal member along itshorizontal span. The internal shape of the internal compartment maynarrow towards a distant position from the connector. The narrowing maybe gradual or non-gradual. The narrowing may be linear, logarithmic, orexponential. The internal compartment of the material removal member mayhave a shape that allows movement of the pre-transformed material withinthe compartment. The movement of the pre-transformed material within thecompartment may comprise laminar or curved movement. The curved movementmay comprise a spiraling movement. The curved movement may comprise ahelical movement. The internal compartment may have an internal shape ofa helix, spiral, or screw. The screw may be a narrowing screw, acylindrical screw, or any combination thereof (e.g., a household typescrew, or an Archimedean screw). Viewed from below, the opening port ofthe nozzle may horizontally overlap the internal compartment (e.g.,centered below as shown for example in FIG. 28A), or not overlap. Insome embodiments, the opening port of the nozzle is horizontallyseparated from the internal compartment by a gap (e.g., FIG. 33, 3313).The power source, reservoir, and/or internal compartment may bestationary or translational with respect to the material bed. Thematerial removal mechanism (or any of its components) may translaterelative to the material bed. For example, the material removalmechanism may be stationary, and the material bed may be translating.For example, the material removal mechanism may translate, and thematerial bed may be stationary. For example, both the material removalmechanism and the material bed may be translating (e.g., in the samedirection, in opposite directions and/or at different speeds).

In some embodiments, the shape of the internal compartment, openingport, and/or nozzle reduces turbulence of the pre-transformed materialas it travels towards the power source. The shape of the internalcompartment, opening port, and/or nozzle may substantially preventturbulence of the pre-transformed material as it travels towards thepower source. The shape of the internal compartment, opening port,and/or nozzle may promote a spiral and/or helical flow of thepre-transformed material as it travels towards the power source. Theshape of the internal compartment, opening port, and/or nozzle maypromote a laminar flow of the pre-transformed material as it travelstowards the power source.

In some embodiments, pre-transformed material from the material bedrelocates into the material removal mechanism through a materialentrance port. The relocation may be induced by an attractive force(e.g., vacuum, electrostatic force, and/or magnetic force). Therelocation may be actively induced. The active inducement may be by agas flow (e.g., positive or negative), magnetic force, and/orelectrostatic force. The relocated pre-transformed material enteringthrough the entrance port (e.g., nozzle opening) may travel into aninternal compartment. The relocated pre-transformed material may travelthrough the internal compartment towards the power source. The relocatedpre-transformed material may travel through the opening (e.g., entrance)port towards the power source. The relocated pre-transformed materialmay travel through the opening (e.g., entrance) port towards the powersource, into a reservoir. The relocated pre-transformed material mayaccumulate in the reservoir. The relocated pre-transformed material inthe reservoir may be recycled and re-used (e.g., by the materialdispensing mechanism) to provide at least a portion of the material bed.The recycling may be before, after, and/or during the formation of: the3D object, layer of hardened material, transformed material, or anycombination thereof. The reservoir can be disposed horizontally above,on the same plane, or below the entrance opening port (e.g., nozzleentrance opening) of the material removal member.

The multiplicity of opening ports (e.g., material entrance ports, ornozzle opening ports) of the material removal mechanism may be arrangedin groups (e.g., 2823), in an array, in a single file (e.g., 2932),staggered file (e.g., 2923 and 2924), randomly, or any combinationthereof. The opening port of the material removal mechanism may be asingle opening port or a multiplicity of opening ports.

In some embodiments, the pre-transformed material accumulates in theinternal compartment of the material removal mechanism. The opening portthrough which material enters the material removal mechanism, may beaway from the position in which the pre-transformed material accumulatesin the internal compartment. Away may be vertically and/or horizontallyaway. Away may be distant. Away may be in a position that substantiallyprevents the pre-transformed material to flow back into the opening portthrough which it entered (e.g., and back into the material bed). Awaymay be in a position that allows the pre-transformed material to betrapped in the internal compartment and not fall back to the materialbed (e.g., through the opening port). Away may be in a position thatallows the pre-transformed material to flow into the reservoir. FIG. 33shows an example of a side view of a material removal mechanism having anozzle 3302 through which pre-transformed material flows inwards 3301towards the internal compartment of the material removal mechanism 3303.Nozzle 3302 is but one example that represents any nozzle (e.g., FIG.15). In the example shown in FIG. 33, the pre-transformed material isflowing (e.g., in a spiraling motion 3304) toward a connection 3305. Theconnection can connect the internal compartment to a reservoir 3307(e.g., through a channel (e.g., hose) 3306). The connection can connectthe internal compartment to a force source 3309 (e.g., through a channel(e.g., hose) 3310). Internal compartment 3310 is but one example thatrepresents any internal compartment (e.g., FIGS. 28A-C, or FIGS. 29A-E).The force source can connect to the internal compartment, to thereservoir, or to both. The reservoir can connect directly or indirectlyto the internal compartment. The internal compartment can connectdirectly or indirectly to the nozzle. In some examples, the nozzle hasan entrance port 3300 through which the pre-transformed material entersthe material removal mechanism. The material removal mechanism may beseparated from the exposed surface of the material bed (e.g., 3315) by agap (e.g., 3312). In some examples, the material removal mechanismcontacts the material bed. For example, the opening port may contact theexposed surface of the material bed. The material removal mechanism maytranslate laterally (e.g., 3314) along the material bed. For example, insome embodiments, the pre-transformed material (e.g., and/or debris) inthe internal compartment of the material removal mechanism is evacuated(e.g., using a second force source) while the material dispensingmechanism is outside of the area occupied by the target surface (e.g.,the material bed). The first force source may be chosen such that it maynot (e.g., substantially) evacuate the pre-transformed material (e.g.,and/or debris) in the internal compartment. In some embodiments, thedimensions and/or shape of the internal compartment are chosen such thatthe pre-transformed material (e.g., and/or debris) that is evacuatedfrom the target surface while planarizing it, will not overburden theevacuation operation by the first force source. In some embodiments, thesecond force (e.g., and/or second force source) is chosen such that thepre-transformed material (e.g., and/or debris) that is evacuated fromthe target surface while planarizing it, will not overburden theevacuation operation by the first force source. In some embodiments, thefirst force (e.g., and/or first force source) is chosen such that thepre-transformed material (e.g., and/or debris) that is evacuated fromthe target surface while planarizing it, will not overburden theevacuation operation by the first force source. The second force maycomprise compressed and reduced pressure. For example, when a forcesource is a pump (e.g., peristaltic pump), the pump pressurized gas onone of its ends, and a reduced pressure at another of its ends. One pumpend (e.g., forming pressurized gas) may operatively couple to one sideof the internal compartment (e.g., 4328), while the other pump end mayoperatively couple to the other side of the internal compartment (e.g.,4329). The coupling may be direct or indirect.

FIG. 43A shows an example of a side view of a material removal mechanism4301 that can translate vertically, horizontally, and/or at an angle(e.g., 4302). Pre-transformed material and/or debris from the targetsurface 4303 is attracted by a force source 4304 (e.g., vacuum pump)into an internal compartment 4305, through a nozzle 4306, as depicted bythe dotted arrows. The attracted pre-transformed material and/or debrisaccumulates in a portion of the internal compartment 4307 during theplanarization operation of the material removal member. After at leastone planarization operation by the material removal mechanism, theaccumulated pre-transformed material and/or debris can be removed. Theirremoval may utilize a second force source (e.g., 4310), such as forexample, a pressurized gas that is injected through an entrance opening(e.g., 4308), and expelled through an exit opening (e.g., that isopposing this entrance opening) and allow outflow of the accumulatedpre-transformed material through a channel (e.g., 4309).

FIG. 43B shows an example of a front view of a material removalmechanism 4320 that can translate according vertically, horizontally,and/or at an angle 4302. Pre-transformed material and/or debris from thetarget surface 4323 is attracted by a source force 4324 into an internalcompartment 4325, through a nozzle 4326, as depicted by the dottedupward pointing arrows. After at least one planarization operation bythe material removal mechanism, the accumulated pre-transformed materialand/or debris can be removed. Their removal may utilize a second forcesource (e.g., 4330), such as for example, a pressurized gas that isinjected through an entrance opening (e.g., 4328), and expelled throughan exit opening (e.g., 4329, e.g., that is opposing this entranceopening) and allow outflow of the accumulated pre-transformed materialthrough a channel (e.g., 4331). Their removal may optionally oradditionally utilize a third force source opposite to the second forcesource (e.g., in type and/or amount) that removes (e.g., or aids inremoval of) the accumulated pre-transformed material from the internalcompartment. For example, the third force source may be (e.g., directlyor indirectly) coupled to the opening 4329. The expelled pre-transformedmaterial and/or debris may be treated in a treatment station 4332. Thetreatment station may comprise separation, sorting, or reconditioning.For example, it may be separated (e.g., using a material separator). Thematerial separator may comprise a filter (e.g., sieve, and/or membrane),separation column, and/or cyclonic separator. For example, it may besorted as to material type and/or size. For example, it may be sortedusing a gas classifier that classifies gas-borne material (e.g., liquidor particulate) material. For example, using an air-classifier. Forexample, using a powder gas classifier. The reconditioning may compriseremoving of an oxide layer forming on any particulate material.Reconditioning may comprise physical and/or chemical reconditioning. Thephysical reconditioning may comprise ablation, spattering, blasting, ormachining. The chemical reconditioning may comprise reduction. Theexpelled (and/or treated) pre-transformed material may be accumulated ina reservoir 4333. The accumulated material in the reservoir 4333 may berecycled and/or reused in the 3D printing (e.g., by the materialdispensing mechanism).

The material removal mechanism may optionally comprise an equilibrationchamber (e.g., sown as side view 4311 and front view 4331). Theequilibration chamber may equilibrate the gas pressure within theequilibration chamber to be (e.g., substantially) equal from one of itssides (e.g., 3355) to its opposing side (e.g., 4334), such that when thematerial removal member attracts pre-transformed material from thetarget surface, the force excreted on this pre-transformed material willbe (e.g., substantially) equal along (i) the width (e.g., 4336) of thematerial dispensing mechanism nozzle (e.g., 4336) opening and/or (ii)the width of the target surface (e.g., 4323).

The force source may be connected to the internal compartment (e.g.,optionally through the equilibration chamber) through one or moreopenings. The connection may be through rigid and/or flexible channels.The channels may have a narrowing or constant cross section. Theconnection may be through one or more slits. The openings may be (e.g.,substantially) constant and/or varied. For example, positions closer tothe force source may have narrower openings, than positions farther awayfrom the force source.

FIG. 44A shows an example of a front view of a force source 4401 that isconnected to a chamber 4402 (e.g., equilibration chamber, or internalcompartment) of the material removal mechanism through a channel 4403.The flow of attracted material and/or gas is schematically shown by thedotted arrows in FIG. 44A. The chamber may comprise an aerodynamic shape(e.g., 4402). The upward flowing gas and/or material may flow upward ina direction opposite to the target surface and/or the gravitationalcenter through one (e.g., shown in FIG. 44B, 4421) or more (e.g., FIG.44D, 4441) material and/or gas openings. The material and/or gasopenings may be slits. The one or more material and/or gas openings maybe (i) the opening of the nozzle (e.g., FIG. 43, 4312), (ii) the opening(e.g., 4313) between the internal compartment (e.g., 4305) and thepressure equilibration chamber (e.g., 4311), (iii) the opening (e.g.,4314) between the gas equilibration chamber (e.g., 4311) and the forcesource (e.g., 4304), (iv) the opening between the internal compartment(e.g., FIG. 14, 1403) and the force source (e.g., 1401) (e.g., in casethere is no pressure equilibration chamber).

FIG. 44C shows an example of a front view of a force source 4431 that isconnected to a chamber 4432 (e.g., equilibration chamber, or internalcompartment) of the material removal mechanism through a plurality ofchannels (e.g., 4433). The flow of attracted material and/or gas isschematically shown by the dotted arrows in FIG. 44C. The cross sectionof the channel may be rectangular (e.g., 4421, e.g., square), orelliptical (e.g., round, e.g., 4441). The cross section of the channelmay be oval. FIG. 44D show an example of a bottom view of materialand/or gas openings that are equal in cross section. FIG. 44F show anexample of a bottom view of material and/or gas openings that areunequal in cross section. The force source may comprise one (e.g., 4404)or more (e.g., 4434) openings. The force source may connect to a channelbundle. FIG. 44E shows an example of a channel bundle cross section4442. The channels in the bundle may separate further away from theforce source, and connect (e.g., separately) to the internal compartmentand/or pressure equilibration chamber of the material removal mechanism.FIG. 44E shows an example of a force source 4461 that has an exitopening 4463 to which a channel bundle is connected, which channels areseparated (e.g., 4464) and connect to the internal compartment orpressure equilibration chamber 4462 in material and/or gas openings 4465respectively. In FIG. 44E, the material and/or gas openings are variedin cross section. FIG. 44F shows a bottom view of the material and/orgas openings that are varied in cross section. The gas equilibrationchamber and/or varied location, and/or shape (e.g., FLS) of the materialand/or gas openings may facilitate a homogenous pressure distributionalong the nozzle opening. The area of the horizontal cross section ofthe nozzle entrance opening (e.g., FIG. 29A, 2912) is greater by atleast about 2 times (“*”), 3*, 5*, 10*, 15*, 30*, or 50* the verticalcross section of the internal compartment of the material removalmechanism (e.g., FIG. 33, 3303). The nozzle entrance opening is shown,for example, in FIG. 33, 3300.

The In some embodiments, the internal compartment can connect to one ormore force sources. For example, the internal compartment can connect totwo force sources. For example, the internal compartment can connect toa vacuum source and to a pressurized air source. The transformedmaterial that is attracted into the internal compartment can rest there(e.g., be trapped there). For example, the curved surface 3320 mayfacilitate concentrating the pre-transformed material within theinternal compartment. This concentrated material may be disposed in amanner that will minimally (e.g., not) hinder attracting subsequentpre-transformed material from entering the internal compartment. In someembodiments, the pre-transformed material (and/or debris) that entersthe internal compartment occupies at most about 50%, 40%, 20%, 10%, or10% of the internal compartment volume. In some embodiments, thepre-transformed material is attracted into the internal compartmentusing a first force source, and is evacuated from the internalcompartment using a second source force that is different from the firstforce source in its intensity and/or type. The evacuation of thepre-transformed material (and/or debris) from the internal compartmentcan be during, before, and/or after the planarization operation of thetarget surface by the material removal mechanism. For example, thematerial removal mechanism may planarize a powder bed layer whilesucking powder material using vacuum, which sucked powder materialaccumulates in the internal compartment; and after the planarizationoperation a pressurized air flows into the internal compartment (e.g.,with or without blocking the nozzle opening) and evacuates theaccumulated powder material (e.g., through the opening 3305). Thepressurized air may be directed towards the exit opening (e.g., 3305).In some embodiments, after the accumulated powder material has beenremoved from the internal compartment, the material removal mechanism isready to suck and planarize a new layer of powder material.

In some embodiments, the operation of the material removal mechanismcomprises separating the pre-transformed material (e.g., particulatematerial) from a gas (e.g., in which the pre-transformed material iscarried in) without the use of one or more filters. For example, theoperation of the material removal mechanism comprises can comprise avortex separation (e.g., using a cyclone). For example, the operation ofthe material removal mechanism can comprise a centrifugal separation(e.g., using a cyclone). FIG. 42 shows an example of an internalcompartment 4225 of the material removal mechanism. In some embodiment,the internal compartment of the material removal member comprises acyclone. In some embodiments, the material removal mechanism comprises acyclonic separator. In some embodiments, the material removal mechanismcomprises cyclonic separation. The operation of the material removalmechanism can comprise gravitational separation. The operation of thematerial removal mechanism can comprise rotation of the pre-transformedmaterial and/or debris (e.g., in the internal compartment of thematerial removal mechanism).

In some embodiments, the pre-transformed material that is attracted tothe force source rests at the bottom of the internal compartment of thematerial removal mechanism. Bottom may be towards the gravitationalcenter, and/or towards the target surface. The force source can be avacuum source that may be connected to internal compartment (e.g., at atop position, e.g., 4224). The pre-transformed material may be suckedinto the internal compartment from the target surface (e.g., 4420)through the nozzle (e.g., 4201) into the internal compartment (e.g.,4225). The gas(es) that is sucked with the pre-transformed material intothe internal compartment (e.g., 4215) may rotate within at a rotationalspeed to form a cyclone. The internal compartment may comprise a conehaving its long axis perpendicular to the target surface and/or itsnarrow end pointing towards the target surface (e.g., 4220).Alternatively, the internal compartment may comprise a cone having itslong axis parallel to the target surface and/or its narrow end pointingtowards a side wall of the enclosure. The gas may flow in the internalcompartment in a helical pattern along the long axis of the cyclone.During the process, the pre-transformed material (and/or debris) suckedinto the cyclone, may concentrate at the walls of the cyclone (e.g.,4214) and gravitate to and accumulate at its bottom (e.g., 4220). Theaccumulated pre-transformed material (e.g., and/or debris) may beremoved from the bottom of the cyclone. For example, after one or moreoperation of planarizing a layer of pre-transformed material in thematerial bed, the bottom of the cyclone may be opened and theaccumulated pre-transformed material (e.g., and/or debris) within may beevacuated. In some examples, the pre-transformed material that entersthe internal compartment of the material removal member is of a firstvelocity, and is attracted towards the force source (e.g., 4210), thatis connected to the internal compartment through a connector 4224. Onits way to the connector, the pre-transformed material may lose itsvelocity in the internal compartment and precipitate at the bottom ofthe cyclone. In some examples, the gas(es) material that enters theinternal compartment of the material removal member from the nozzle isof a first velocity, and is attracted towards the force source (e.g.,4210), that is connected to the internal compartment through a connector4224. On its way to the connector, the gas(es) material may lose itsvelocity in the internal compartment, for example, due to an expansionof the cross section of the internal compartments (e.g., diameter 4422is smaller than diameter 4221). An optional hurdle (e.g., 4216) may beplaced to exacerbate the volume difference between portions of thecyclone that are closer to the exit opening (e.g., 4224) relative tothose further from the exit opening.

In some examples, a secondary air flow can flow into the cyclone (e.g.,4223) from an optional gas opening port (e.g., 4217). The gas openingport may dispose adjacent to the nozzle (e.g., at the same side of thenozzle with respect to the direction of travel (e.g., 4203). The gasopening port may be disposed at a direction relative to the direction oftravel, that is different from the direction where the nozzle isdisposed. The secondary air flow may reduce abrasion of the internalsurface of the internal compartment walls (e.g., 4214). The secondaryair flow may push the pre-transformed material from the walls of theinternal compartment towards the narrow end of the cyclone (e.g., whereit is collected). The secondary

The layer dispensing mechanism may comprise a planarizing (e.g.,flattening) mechanism. The planarizing mechanism may comprise a levelingmechanism (e.g., FIG. 13, 1306 and 1304) or a material removal mechanism(e.g., 1303). The layer dispensing mechanism may comprise a materialdispensing mechanism (e.g., FIG. 13, 1305) and a planarizing mechanism.The layer dispensing mechanism may be movable (e.g., in the direction1300). The layer dispensing mechanism may be movable horizontally,vertically or at an angle. The layer dispensing mechanism may be movablemanually and/or automatically (e.g., controlled by a controller). Themovement of the layer dispensing mechanism may be programmable. Themovement of the layer dispensing mechanism may be predetermined. Themovement of the layer dispensing mechanism may be according to analgorithm. The layer dispensing mechanism may travel laterally (e.g.,substantially) from one end of the material bed, to the opposite end toeffectuate disposal of a planarized layer of pre-transformed material onthe exposed surface of the material bed or platform.

In some examples, the layer dispensing mechanism comprises at least onematerial dispensing mechanism and at least one planarizing mechanism.The at least one material dispensing mechanism and at least oneplanarizing mechanism may be connected or disconnected. The blade of theleveling mechanism may be tapered. Examples of tapered blades aredisclosed in PCT/US15/36802, which is incorporated herein by referencein its entirety.

The material dispensing mechanism can operate in concert with theplanarizing mechanism (e.g., shearing blade and/or vacuum suction)and/or independently with the planarizing mechanism. At times, thematerial dispensing mechanism (e.g., powder dispenser) proceed beforethe leveling mechanism, that proceeds before the material removalmechanism, as they progress along the material bed (e.g., laterally). Attimes, the material dispensing mechanism may proceed before the materialremoval mechanism, as they progress along the material bed. At times,the material dispensing mechanism may proceed before the levelingmechanism as they progress along the material bed. The planarizingmechanism may include the material removal mechanism and/or the levelingmechanism. The material dispensing mechanism or any part thereof (e.g.,its internal reservoir) may freely vibrate. The vibrations may beinduced by one or more vibrators. The material dispensing mechanism orany part thereof may vibrate without substantially vibrating theplanarizing mechanisms. The material dispensing mechanism or any partthereof may vibrate without substantially vibrating the material removalmechanism and/or the leveling mechanism. The material dispensingmechanism may be connected to the planarizing mechanism by a compliantmounting. The compliant mounting may allow the planarizing mechanism toattach and/or detach from the material dispensing mechanism. FIGS. 34A-Dshow side view examples of layer dispensing mechanisms comprising amaterial dispensing mechanism (e.g., 3411) attached to a planarizingmechanism (e.g., material removal mechanism 3413, or leveling mechanism3423); attached through compliant mounting (e.g., FIG. 34A, 3412 and3414; and FIG. 34B, 3422 and 3424). In some examples, the compliantmounting comprises two separate parts that are intertwined with eachother. FIG. 34D shows an example of two configurations of compliantmountings: the first including 3442 and 3444, and the second including3446 and 3448. In an embodiment where the planarizing mechanismcomprises two components (e.g., the leveling mechanism and the materialremoval mechanism), at least one of the components may be connected by acompliant mounting. For example, each one of the components may beconnected by a compliant mounting (e.g., FIG. 34D), or one of thecomponent may be connected by a compliant mounting (e.g., FIG. 34C).

FIG. 34A shows an example of a layer dispensing mechanism comprising: amaterial dispensing mechanism 3411 which is connected by a compliantmounting 3412 and 3414 to a material removal mechanism 3413; which layerdispensing mechanism is disposed above the material bed 3415. FIG. 34Bshows an example of a layer dispensing mechanism comprising: a materialdispensing mechanism 3421 which is connected by a compliant mounting3422 and 3424 to a leveling mechanism 3423; which layer dispensingmechanism is disposed above the material bed 3425. FIG. 34C shows anexample of a layer dispensing mechanism comprising: a materialdispensing mechanism 3431 which is connected by a compliant mounting3432 and 3434 to a leveling mechanism 3433, which in turn is (e.g.,directly) connected (e.g., 3436) to a material removal member 3437;which layer dispensing mechanism is disposed above the material bed3435. FIG. 34D shows an example of a layer dispensing mechanismcomprising: a material dispensing mechanism 3441 which is connected by acompliant mounting 3442 and 3444 to a leveling mechanism 3443, which inturn is connected by a compliant mounting 3446 and 3448 to a materialremoval mechanism 3447; which layer dispensing mechanism is disposedabove the material bed 3445.

The distance between the functionalities of the various components ofthe layer dispensing mechanism is referred to herein as the“distance-between-functionalities.” The distance-between-functionalitiescan be at least about 100 μm, 150 μm, 200 μm, 300 μm, 400 μm, 500 μm,600 μm, 700 μm, 800 μm, 900 μm, or 1000 μm. Thedistance-between-functionalities can be at most about 1000 μm, 900 μm,800 μm, 700 μm, 60 μm, 500 μm, 450 μm, 400 μm, 350 μm, 300 μm, 250 μm,200 μm, or 150 μm. The distance-between-functionalities can be of anyvalue between the afore-mentioned values (e.g., from about 100 μm toabout 1000 μm, 100 μm to about 500 μm, 300 μm to about 600 μm, 500 μm toabout 1000 μm). In some examples, the distance between the blade (e.g.,tip thereof) of the leveling mechanism and the opening port of thematerial removal mechanism is equal to thedistance-between-functionalities. In some examples, the distance betweenthe blade (e.g., tip thereof) of the leveling mechanism and the openingport of the material dispensing mechanism (or of the material fall) isequal to the distance-of-functionalities. In some examples, the distancebetween the opening port of the material dispensing mechanism (or of thematerial fall) and the opening port of the material removal mechanism isequal to the distance-of-functionalities. The material fall (e.g., FIG.13, 1307) is formed when the material is dispensed from the materialdispensing mechanism through the opening port (e.g., exit opening port)towards the platform (e.g., towards the material bed). The components ofthe layer dispensing mechanism (e.g., material dispensing mechanism,material removal mechanism, and/or leveling mechanism) can be evenly ornon-evenly spaced. For example, the blade (e.g., tip hereof), entranceopening port of the material removal mechanism, and exit opening port ofthe material dispensing mechanism may be evenly or non-evenly spaced.

The force exerted by the force source through the material removalmechanism may cause at least a portion of the pre-transformed material(e.g., powder particles) to lift (e.g., become airborne) from thematerial bed, and travel (e.g., influx) towards the entrance port of thematerial removal mechanism (e.g., nozzle entrance). The liftedpre-transformed material (or at times, unwanted transformed material)may further travel (e.g., flow) within the material removal mechanism(e.g., within the internal compartment and/or within the nozzle). Theinflux may comprise laminar, turbulent, or curved movement of the liftedpre-transformed material. The influx may be towards the reservoir. Theinflux may be towards the force source. The gap between the exposedsurface of the material bed and the entrance port of the materialremoval mechanism (e.g., nozzle entrance) may depend on the average FLSand/or mass of the pre-transformed material sections (e.g., particulatematerial). The gap between the exposed surface of the material bed andthe entrance port of the material removal mechanism (e.g., nozzleentrance) may depend on the mean FLS and/or mass of the particulatematerial. The structure of the internal compartment and/or nozzleenables uniform removal of pre-transformed material from the materialbed. In some examples, the amount of force generated by the force sourceand/or its distribution through the internal compartment and/or nozzleof the material removal mechanism enables uniform removal ofpre-transformed material from the material bed. For example, thestructure of the internal compartment and/or nozzle enables uniformsuction of pre-transformed material from the material bed. The structureof the internal compartment and/or nozzle may influence the velocity ofthe influx of pre-transformed material into the material removalmechanism. The amount of force generated by the force source and/or itsdistribution through the internal compartment and/or nozzle of thematerial removal mechanism may influence the homogeneity of the influxvelocity along the entrance port(s) and/or along the material bed.

The layer dispensing mechanism (e.g., recoater) may dispense a portionof a layer of pre-transformed material. The dispensed portion of a layerof pre-transformed material may comprise an exposed surface that is(e.g., substantially) planar (e.g., horizontal, flat, smooth, and/orunvaried). FIG. 10A shows an example of a material bed 1012 comprising asubstantially planar exposed surface 1013 in which at least a portion ofa 3D object 1011 was generated from a portion of the material bed 1012by irradiation of the energy beam 1014, thus forming a depression 1016in the material bed.

In some embodiments, a sub layer may be formed in the material bed. Asub layer has a height that is less than a height of a (e.g., typical)layer of hardened material in of the 3D object. A sub-layer may beformed from the same (e.g., first) or from a different (e.g., second)pre-transformed material, as compared to the layer of hardened material.FIG. 10B shows an example of a material bed 1022 disposed in anenclosure 1025, in which a layer of hardened material 1021 is disposedin a material bed 1022 comprising a first pre-transformed material, anda sub-layer of a second pre-transformed material 1026 is disposed in thedepression formed in the material bed upon formation of the hardenedmaterial 1021. At least a portion of the second pre-transformed materialmay be irradiated by an energy beam to form a transformed material. FIG.10C shows an example of a layer of transformed material 1031 that wasformed from a first pre-transformed material of the material bed 1032,thus forming a depression 1036, that was filled in part by a sub-layerof a second pre-transformed material 1037, a part of which wastransformed by the energy beam 1034 to form a sub-layer of transformedmaterial 1038 that is of a different type than the transformed materialof the layer 1031. The different pre-transformed material may differ inits microstructure, FLS, overall physical structure, chemicalcomposition, or any combination thereof. The different may be in theheight of the layers and sub-layers. For example, the sub layercomprising the second pre-transformed material may have a smaller height(e.g., FIG. 10B “h”) as compared to the layer of the firstpre-transformed material. The first pre-transformed material may besubstantially identical or different than the second pre-transformedmaterial. The difference in microstructure may comprise difference inmelt pool metrology, crystal structure, or crystal structure repertoire(e.g., relative abundance and placement of various crystal structureswithin a melt pool). The melt pool metrology may comprise their FLS,and/or depth. By repeating such process, 3D objects may be formed inwhich various layers, or portions of layers, differ. FIG. 11A shows anexample of a vertical cross section of a 3D object comprising layers ofdifferent material types according to color coding (e.g., each colorrepresents one type of material). FIG. 11B shows an example of avertical cross section of a 3D object comprising layers of substantiallythe same material, but having different microstructure (e.g., melt poolsizes).

A substantially planar exposed surface of the material bed may comprisea substantially uniform pre-transformed material (e.g., powder) heightof the exposed surface. The layer dispensing mechanism (e.g., levelingmember) can provide material uniformity height (e.g., powder uniformityheight) across the exposed layer of the material bed such that portionsof the bed that are separated from one another by at least about 1 mm, 2mm, 3 mm, 4 mm, 5 mm, or 10 mm, have a height deviation of at most about10 mm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, 500 μm, 400μm, 300 μm, 200 μm, 100 μm, 90 μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30μm, 20 μm, or 10 μm. The layer dispensing mechanism can provide materialuniformity across the exposed layer of the material bed such thatportions of the bed that are separated from one another by any valuebetween the afore-mentioned height deviation values (e.g., from about 1mm to about 10 mm) have a height deviation from about 10 mm to about 10μm. The layer dispensing mechanism may achieve a deviation from a planaruniformity of the exposed layer of the material bed (e.g., horizontalplane) of at most about 20%, 10%, 5%, 2%, 1% or 0.5%, as compared to anideal planarity. The layer dispensing mechanism may achieve a deviationfrom a planar uniformity of the exposed layer of the material bed (e.g.,horizontal plane) of at most about 150 μm, 130 μm, 100 μm, 70 μm, 50 μm,40 μm, 30 μm, 2 μm, 10 μm or 5 μm. The layer dispensing mechanism mayachieve a deviation from a planar uniformity of the exposed layer of thematerial bed between any of the afore-mentioned values (e.g., from about5 μm to about 150 μm, from about 5 μm to about 50 μm, from about 30 μmto about 100 μm, or from about 100 μm to about 150 μm).

The material removal mechanism may remove at least a portion (e.g., theentire) of at least the exposed surface of the material bed. The atleast a portion may be at a designated location (e.g., controlledmanually or by the controller). For example, the material removalmechanism may form depressions (e.g. voids) in a material bed comprisinga first pre-transformed material, which depressions may be subsequentlyfiled with a layer or sub-layer of a second pre-transformed material.The second pre-transformed material may be substantially identical, ordifferent from the first pre-transformed material. The sub layer may besmaller from a layer with respect to their height and/or horizontalcross section.

The layer dispensing mechanism (e.g., material removal mechanism) mayfacilitate the formation of a 3D object that has a locally differentmicrostructure. The locally different microstructure can be betweendifferent layers, or within a given layer. For example, at least oneportion of a layer within the 3D object may differ from another portionwithin that same layer, in terms of its microstructure. Themicrostructure difference may be any difference recited above.

In another aspect, the system and apparatuses for generating the 3Dobject(s) comprises a mechanism for separating the 3D object(s) from theremainder of the material bed that is not the 3D object, and/or cleaningthe 3D object (e.g., within the enclosure). In some embodiments, boththe material bed and the mechanism for separating the 3D object(s) fromthe remainder of the material bed that is not the 3D object are enclosedin the same atmosphere. The atmosphere can be an inert, non-reactive,oxygen depleted, humidity depleted, or passive atmosphere with respectto the material bed, pre-transformed material, and/or 3D object. FIG. 16shows an example of a system and apparatuses to clean a 3D object 1606that is formed in a material bed 1604 in a first portion of theenclosure (e.g., 1617), by pushing the 3D object with the remainder ofthe material bed (or a portion thereof that surrounds the 3D object) bya pushing mechanism 1619 through an opening 1618 to a second portion ofthe enclosure (e.g., 1616) along a direction indicated by the boldarrows 1631, 1604 respectively. The 3D object is separated (e.g.,released or relieved) from the remainder of the material bed (or apushed portion thereof) at the second portion of the enclosure. The 3Dobject may be subsequently cleaned and/or cooled within the enclosure(e.g., at the second enclosure portion), and/or exit the enclosurethrough an exit 1614 along the direction indicated by the bold arrow1634, to a position 1608 outside of the enclosure 1600. The cleaning maycomprise using gas pressure (e.g., positive and/or negative), vibration,and/or surface friction (e.g., brush). The cleaning may comprise a postprocessing procedure as disclosed in PCT/US15/36802, which isincorporated herein by reference in its entirety. FIG. 16 shows andexample of a material bed 1604 disposed on a platform comprising asubstrate 1609, a base 1602, sealant 1603 that encloses the materialwithin the material bed, a vertical actuator 1605 that is enablesvertical travel 1612 of the platform. The sealant 1603 prevents thematerial within the material bed 1604 to penetrate the environment 1610where the actuator is operational, and reach the bottom of the enclosure1611. The 3D object is formed in the example of FIG. 16, by using anenergy source 1624 that irradiates an energy beam, which energy beamtravels through an optical system 1621 and an optical window 1615 intothe enclosure environment, and interacts with the material bed totransform a portion thereof as part of the 3D object 1606.

In some embodiments, the 3D object is devoid of surface features thatare indicative of the use of a post printing process. In someembodiments, the 3D object is including surface features that areindicative of the use of a post printing process. The post printingprocess may comprise a trimming process (e.g., to trim auxiliarysupports). The trimming process may comprise ablation by an energy beam(e.g., laser), mechanical, or chemical trimming. The trimming processmay be an operation conducted after the completion of the 3D printingprocess (e.g., using the pre-transformed material). The trimming processmay be a separate operation from the 3D printing process. The trimmingmay comprise cutting (e.g., using a piercing saw). The trimming cancomprise polishing or blasting. The blasting can comprise solidblasting, gas blasting, or liquid blasting. The solid blasting cancomprise sand blasting. The gas blasting can comprise air blasting. Theliquid blasting can comprise water blasting. The blasting can comprisemechanical blasting.

In some embodiments, the cooling of the 3D object (e.g., in the secondenclosure portion, e.g., 1616) comprises using a cooling agent, or acooling mechanism. The cooling mechanism may be active or passive. Thecooling may comprise any cooling mechanism or agent as disclosed inPCT/US16/59781, and in U.S. 62/252,330, both of which are incorporatedherein by reference in their entirety. The enclosure may comprise a mesh(e.g., 1625). The mesh may prevent the 3D object from passing through,and allow at least the pre-transformed material to go through (e.g.,1626). The at least pre-transformed material that passes through themesh may accumulate 1605 in the reservoir 1613. The cleaning and/orcooling mechanisms may be coupled and controlled by a controller, and/ormanually. The mesh may be disposed adjacent to the material bed.Adjacent may comprise above, below, or to the side (e.g., 1625). In someexamples, the material bed (e.g., and the platform (1609 and 1602) onwhich the material bed rests) may be translatable vertically (e.g.,1612). In some examples, the mesh may be translated vertically. Theplatform and/or mesh may be translatable vertically, horizontally,and/or in an angle (e.g., planar or compound). The translation may bebefore, after, and/or during at least a portion of the 3D printing. Insome examples, the mesh aligns with the platform of the material bed. Insome examples, the mesh aligns with a positing at or below the bottomskin layer of the 3D object. In some examples, the mesh aligns whileconsidering the vertical position of the platform and/or bottom skinlayer of the 3D object. The movement of the platform and/or mesh may becontrolled by the controller, and/or be operatively coupled thereto. Thecontroller may direct alignment of the platform and/or mesh at the end,before and/or during at least a portion of the 3D printing process. Thematerial bed may border by sides (e.g., planes, planks, or slates) thatprevent the material within the material bed from spilling. At least twoof the (e.g., opposing) sides may comprise side openings, or may betranslational (e.g., horizontally (e.g., 11619 and 1631), vertically(e.g., 1618 and 1633) or at an angle). The side openings may be opened,closed, or translated automatically and/or manually. The side openingsmay be controlled by the controller. The side openings may be situatedopposite to each other (e.g., along a line). AT least one of the sideopenings may comprise a first gate (e.g., 1618). The enclosure maycomprise a second gate (e.g., 1614) disposed as part of its confiningface (e.g., wall, 1607). The gate (e.g., first and/or second) may openhorizontally, vertically, at an angle (e.g., planar or compound), or anycombination thereof. The gate may be a rolling gate. The gate may bemounted to a roller, hinge, and/or rail. At least one of the sideopenings may be pushed to open or comprise a pushing mechanism (e.g., apusher, 1619) comprising a surface. The pushing mechanism (e.g., 1619)may comprise at least one slate, blade, ram, or shovel. The surface(e.g., blade) can comprise a stiff or flexible material. The materialmay be any material disclosed herein. The pushing mechanism maytranslate towards the gate opening (e.g., along a straight line).Examples of gate openings are shown in FIGS. 16, 1618 and 1614. Thepushing mechanism may push at least a portion of the material bed thatis between the pushing surface and the opening that opposes the pushingmechanism. The at least a portion of the material bed that is pushedthorough the opening (e.g., 1618) may comprise one or more printed 3Dobjects (e.g., 1606) embedded within the material bed (e.g., 1604). Insome examples, the 3D object(s) may not be anchored to (e.g., connectedto) at least one of the platform and the side surfaces of the materialbed (e.g., during the generation of the 3D object(s)). In some examples,the 3D object(s) may not be contact (e.g., touch) at least one of theplatform and the side surfaces of the material bed (e.g., 1606). The 3Dobject(s) may comprise auxiliary supports that do not connect to and/orcontact the platform and/or the side surfaces of the material bed (e.g.,during the generation of the 3D object(s)). The 3D object(s) maycomprise auxiliary supports that float anchorlessly in the material bed.The 3D object(s) may be devoid of auxiliary supports during (e.g., andafter) its generation.

In some examples, the at least a portion of the material bed that ispushed through the gate opening (e.g., of the side opening) rests on astage (e.g., deck, balcony, ledge, shelf, slate, slab, plate, or plank).The stage may be substantially planar and/or horizontal. In someinstances, the stage may be non-planar. The stage may comprise one ormore holes. The one or more holes can be open or openable holes. Theholes may be choke holes. The holes can be closed and openedautomatically and/or manually. The opening and/or closing of the holescan be controlled by a controller (e.g., before, during, and/or afterthe 3D printing). The holes can be opened at least in part (e.g., toallow at least the pre-transformed material to flow through). The openholes may prevent the 3D object from passing through. The holes may beclosed by a slab of material that is translatable and/or pivotable. Thetranslation and/or pivoting may be to a position away from the holesand/or stage. The translation and/or pivoting may be towards the bottomof the enclosure. The translation and/or pivoting may be towards thereservoir that collects the material that is separated from the 3Dobject (e.g., 1613). The translation and/or pivoting may allow for atleast partial opening and/or closing of the holes. The one or more holesmay be included in a mesh (e.g., 1625). The holes may allow thepre-transformed material (e.g., of the type in the material bed) to flowthere through (e.g., 1626). The holes may prevent the 3D object to fallthere through (e.g., 1607). The flowing pre-transformed material (orother content of the material bed that is not part of the 3D object(s))may flow through the mesh into a collection-reservoir (e.g., 1613). Thestage may comprise two or more meshes. At least one of the meshes may betranslatable (e.g., horizontally). The translation of the at least oneof the meshes may be from a position which closes the holes, to aposition in which the holes are at least partially open. The translationof the at least one of the meshes may be from a position which opens toholes, to a position in which the holes are at least partially closed.The translation may be a translation of one mesh with respect to asecond mesh. The translation may be a lateral (e.g., horizontal)translation. The translation may be horizontal, vertical, and/or in anangle (e.g., compound or planar angle).

In some instances, the stage (e.g., comprising the mesh 1625) vibrates.For example, the one or holes (e.g., mesh) may be vibrated (e.g., by oneor more vibrator mechanisms). In some instances, the 3D object that isencased by at least the pre-transformed material may be shaken (e.g.,vibrated). In some instances, vibration waves (e.g., ultrasonic waves)may be projected into the 3D object after it has been pushed from thepowder bed (e.g., rests on the stage). The waves may vibrate thepre-transformed material that surrounds the 3D object. The projection ofthe waves may be from a position above, below, or at the verticalposition of the stage. The one or more vibrator mechanism may besituated above, below, or at the vertical position of the stage. The oneor more vibrator mechanism (e.g., vibrator) may be attached to thestage. The one or more vibrator mechanism (e.g., vibrator) may contactor be connected to the stage. The vibrating mechanism (e.g., vibrator orshaker) can be any vibrator mechanism disclosed herein.

The 3D object that is substantially devoid of pre-transformed material(e.g., 1607) may be further cleaned by a gas flow. The gas cleaning maytake place within the enclosure (e.g., 1616), or outside of thereservoir. The pusher (e.g., 1619) may continue and push the 3D objectstowards an exit opening of the enclosure (e.g., 1614), where the 3Dobject can be retrieved (e.g., 1608).

In some instances, one, two, or more 3D objects may be generated in amaterial bed (e.g., a single material bed; the same material bed). Themultiplicity of 3D object may be generated in the material bedsimultaneously or sequentially. For example, at least two 3D objects maybe generated side by side. For example, at least two 3D objects may begenerated one on top of the other. For example, at least two 3D objectsgenerated in the material bed may have a gap between them (e.g., gapfilled with pre-transformed material). For example, at least two 3Dobjects generated in the material bed may contact (e.g., and not connectto) each other. In some embodiments, the 3D objects are independentlybuilt one above the other. The generation of a multiplicity of 3Dobjects in the material bed may allow continuous generation of 3Dobjects.

In some embodiments, the at least one portion of the material bed thatis pushed through the first opening (e.g., 1618) may be disposed in amoving stage. The moving stage may comprise a hole (e.g., it may be amesh). The moving stage may be devoid of a mesh. The moving stage mayrotate. The moving stage may comprise a tumbler mechanism. The movingstage may comprise a rotating drum. The rotating drum may be acentrifuge. The moving stage may allow the pre-transformed material toslide towards a position that is different from the position of the 3Dobject(s) (e.g., due to the relative small weight of the particulatematerial). The stage may translate such that the pre-transformedmaterial may move in a relatively higher velocity (e.g., faster) thanthe 3D object (e.g., that may move negligently). In some embodiments,the stage may not be planar. In some embodiments, the stage may be of asoft material. The stage may comprise a net. For example, the stage maycomprise a flexible net. The 3D object may be cradled by the stage. Insome embodiments, the stage may be absent. In some examples, the systemmay comprise a reservoir (e.g., 1613) for collecting the pre-transformedmaterial that is separated from the 3D object (e.g., 1626). The stagemay comprise a shingle. The shingle may allow at least a pre-transformedmaterial to flow (e.g., seep, or drain) through a hole in the stage, andprevent the 3D object from falling through. The shingles may be randomlysituated or be substantially organized in a pattern (e.g., in rowsand/or columns, and/or relative to the hole(s)). The shingle may beplates or boxes. The shingles may be porous or non-porous. The shinglesmay comprise a soft or a hard material. The shingles may be semi-hard(e.g., gel like substance). The shingles may be of a material thatprevents damage to the 3D object if it falls on the shingles during itsrelease from the material bed (e.g., after being pushed out of the firstopening e.g., 1618).

The FLS of the holes may be adjustable or fixed. In some embodiments,the stage comprises a mesh. The mesh may be movable. The movement of themesh may be controlled manually or automatically (e.g., by acontroller). The relative position of the two or more meshes withrespect to each other may determine the rate at which at least thepre-transformed material passes through the hole (or holes). The FLS ofthe holes may be electrically controlled. The fundamental length scaleof the holes may be thermally controlled. The mesh may be heated orcooled. The stage may vibrate (e.g., controllably vibrate). Thetemperature and/or vibration of the stage may be controlled manually orby the controller. The holes of the stage can shrink or expand as afunction of the temperature and/or electrical charge of the stage. Thestage can be conductive. The mesh may comprise a mesh of standard meshnumber 50, 70, 90, 100, 120, 140, 170, 200, 230, 270, 325, 550, or 625.The mesh may comprise a mesh of standard mesh number between any of theafore-mentioned mesh numbers (e.g., from 50 to 625, from 50 to 230, from230 to 625, or from 100 to 325). The standard mesh number may be US orTyler standards. The two meshes may have at least one position where nopre-transformed material can pass through the holes. The two meshes mayhave a least one position where a maximum amount of material can passthrough the holes. The two meshes can be identical or different. Thesize of the holes in the two meshes can be identical or different. Theshape of the holes in the two meshes can be identical or different. Theshape of the holes can be any hole shape described herein.

In some embodiments, the 3D object comprises layers of hardenedmaterial. The layered structure of the 3D object can be a substantiallyrepetitive layered structure. In some examples, each layer of thelayered structure has an average layer thickness greater than or equalto about 5 micrometers (μm). In some examples, each layer of the layeredstructure has an average layer thickness less than or equal to about1000 micrometers (μm). The layered structure can comprise individuallayers of the successive solidified melt pools. The layer can be formedby depositing droplets or a continuous stream of transformed material.At least two of the successive solidified melt pools can comprise asubstantially repetitive material variation selected from the groupconsisting of variation in grain orientation, variation in materialdensity, variation in the degree of compound segregation to grainboundaries, variation in the degree of element segregation to grainboundaries, variation in material phase, variation in metallurgicalphase, variation in material porosity, variation in crystal phase, andvariation in crystal structure. At least one of the successivesolidified melt pools can comprise a crystal. The crystal can comprise asingle crystal. The layered structure can comprise one or more featuresindicative of solidification of melt pools during the three-dimensionalprinting process. The layered structure can comprise a featureindicative of the use of the three-dimensional printing process (e.g.,as disclosed herein). The three-dimensional printing process cancomprise selective laser melting. In some embodiments, a fundamentallength scale of the three-dimensional object can be at least about 120micrometers.

In some embodiments, the layer of hardened material layer (or a portionthereof) has a thickness (e.g., layer height) of at least about 50 μm,100 μm, 150 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm,900 μm, or 1000 μm. In some examples, the hardened material layer (or aportion thereof) has a thickness of at most about 1000 μm, 900 μm, 800μm, 700 μm, 60 μm, 500 μm, 450 μm, 400 μm, 350 μm, 300 μm, 250 μm, 200μm, 150 μm, 100 μm, 75 μm, or 50 μm. A hardened material layer (or aportion thereof) may have any value in between the afore-mentioned layerthickness values (e.g., from about 50 μm to about 1000 μm, from about500 μm to about 800 μm, from about 300 μm to about 600 μm, from about300 μm to about 900 μm, or from about 50 μm to about 200 μm). In someinstances, the bottom skin layer may be thinner than the subsequentlayers. In some instances, the bottom skin layer may be thicker than thesubsequent layers. The bottom skin layer may have any value disclosedherein for the layer of hardened material. In some instances, the layercomprising the path-of-tiles is thinner than the layers formed withoutusing the path-of-tiles (e.g., formed by the energy beam). In someinstances, the layer comprising the path-of-tiles is thicker than thelayers formed without using the path-of-tiles (e.g., formed by theenergy beam).

The material (e.g., pre-transformed material, transformed material,and/or hardened material) may comprise elemental metal, metal alloy,ceramics, or an allotrope of elemental carbon. The allotrope ofelemental carbon may comprise amorphous carbon, graphite, graphene,diamond, or fullerene. The fullerene may be selected from the groupconsisting of a spherical, elliptical, linear, and tubular fullerene.The fullerene may comprise a buckyball or a carbon nanotube. The ceramicmaterial may comprise cement. The ceramic material may comprise alumina.The material may comprise sand, glass, or stone. In some embodiments,the material may comprise an organic material, for example, a polymer ora resin. The organic material may comprise a hydrocarbon. The polymermay comprise styrene. The organic material may comprise carbon andhydrogen atoms. The organic material may comprise carbon and oxygenatoms. The organic material may comprise carbon and nitrogen atoms. Theorganic material may comprise carbon and sulfur atoms. In someembodiments, the material may exclude an organic material. The materialmay comprise a solid or a liquid. In some embodiments, the material maycomprise a silicon-based material, for example, silicon based polymer ora resin. The material may comprise an organosilicon-based material. Thematerial may comprise silicon and hydrogen atoms. The material maycomprise silicon and carbon atoms. In some embodiments, the material mayexclude a silicon-based material. The solid material may comprise powdermaterial. The powder material may be coated by a coating (e.g., organiccoating such as the organic material (e.g., plastic coating)). Thematerial may be devoid of organic material. The liquid material may becompartmentalized into reactors, vesicles, or droplets. Thecompartmentalized material may be compartmentalized in one or morelayers. The material may be a composite material comprising a secondarymaterial. The secondary material can be a reinforcing material (e.g., amaterial that forms a fiber). The reinforcing material may comprise acarbon fiber, Kevlar®, Twaron®, ultra-high-molecular-weightpolyethylene, or glass fiber. The material can comprise powder (e.g.,granular material) or wires.

The material may comprise a powder material. The material may comprise asolid material. The material may comprise one or more particles orclusters. The term “powder,” as used herein, generally refers to a solidhaving fine particles. The powder may also be referred to as“particulate material.” Powders may be granular materials. The powderparticles may comprise micro particles. The powder particles maycomprise nanoparticles. In some examples, a powder comprising particleshaving an average fundamental length scale of at least about 5nanometers (nm), 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 100 nm, 200 nm, 300nm, 400 nm, 500 nm, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, or100 μm. The particles comprising the powder may have an averagefundamental length scale of at most about 100 μm, 80 μm, 75 μm, 70 μm,65 μm, 60 μm, 55 μm, 50 μm, 45 μm, 40 μm, 35 μm, 30 μm, 25 μm, 20 μm, 15μm, 10 μm, 5 μm, 1 μm, 500 nm, 400 nm, 300 nm, 200 nm, 100 nm, 50 nm, 40nm, 30 nm, 20 nm, 10 nm, or 5 nm. In some cases, the powder may have anaverage fundamental length scale between any of the values of theaverage particle fundamental length scale listed above (e.g., from about5 nm to about 100 μm, from about 1 μm to about 100 μm, from about 15 μmto about 45 μm, from about 5 μm to about 80 μm, from about 20 μm toabout 80 μm, or from about 500 nm to about 50 μm).

The powder can be composed of individual particles. The individualparticles can be spherical, oval, prismatic, cubic, or irregularlyshaped. The particles can have a fundamental length scale. The powdercan be composed of a homogenously shaped particle mixture such that allthe particles have substantially the same shape and fundamental lengthscale magnitude within at most 1%, 5%, 8%, 10%, 15%, 20%, 25%, 30%, 35%,40%, 50%, 60%, or 70%, distribution of fundamental length scale. In somecases, the powder can be a heterogeneous mixture such that the particleshave variable shape and/or fundamental length scale magnitude.

At least parts of the layer can be transformed to a transformed materialthat may subsequently form at least a fraction (also used herein “aportion,” or “a part”) of a hardened (e.g., solidified) 3D object. Attimes a layer of transformed or hardened material may comprise a crosssection of a 3D object (e.g., a horizontal cross section). At times alayer of transformed or hardened material may comprise a deviation froma cross section of a 3D object. The deviation may include vertical orhorizontal deviation. A pre-transformed material may be a powdermaterial. A pre-transformed material layer (or a portion thereof) canhave a thickness (e.g., layer height) of at least about 0.1 micrometer(μm), 0.5 μm, 1.0 μm, 10 μm, 50 μm, 100 μm, 150 μm, 200 μm, 300 μm, 400μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or 1000 μm. Apre-transformed material layer (or a portion thereof) can have athickness of at most about 1000 μm, 900 μm, 800 μm, 700 μm, 60 μm, 500μm, 450 μm, 400 μm, 350 μm, 300 μm, 250 μm, 200 μm, 150 μm, 100 μm, 75μm, 50 μm, 40 μm, 30 μm, 20 μm, 10 μm, 5 μm, or 0.5 μm. Apre-transformed material layer (or a portion thereof) may have any valuein between the afore-mentioned layer thickness values (e.g., from about0.1 μm to about 1000 μm, from about 1 μm to about 800 μm, from about 20μm to about 600 μm, from about 30 μm to about 300 μm, or from about 10μm to about 1000 μm).

In some embodiments, the material composition of at least one layerwithin the material bed differs from the material composition within atleast one other layer in the material bed. The difference (e.g.,variation) may comprise difference in crystal or grain structure. Thevariation may comprise variation in grain orientation, variation inmaterial density, variation in the degree of compound segregation tograin boundaries, variation in the degree of element segregation tograin boundaries, variation in material phase, variation inmetallurgical phase, variation in material porosity, variation incrystal phase, or variation in crystal structure. The microstructure ofthe printed object may comprise planar structure, cellular structure,columnar dendritic structure, or equiaxed dendritic structure.

In some examples, the pre-transformed materials of at least one layer inthe material bed differs in the FLS of its particles (e.g., powderparticles) from the FLS of the pre-transformed material within at leastone other layer in the material bed. A layer may comprise two or morematerial types at any combination. For example, two or more elementalmetals, two or more metal alloys, two or more ceramics, two or moreallotropes of elemental carbon. For example, an elemental metal and ametal alloy, an elemental metal and a ceramic, an elemental metal and anallotrope of elemental carbon, a metal alloy and a ceramic, a metalalloy and an allotrope of elemental carbon, a ceramic and an allotropeof elemental carbon. In some embodiments, all the layers ofpre-transformed material deposited during the 3D printing process are ofthe same material composition. In some instances, a metal alloy isformed in situ during the process of transforming at least a portion ofthe material bed. In some instances, a metal alloy is not formed in situduring the process of transforming at least a portion of the materialbed. In some instances, a metal alloy is formed prior to the process oftransforming at least a portion of the material bed. In a multiplicity(e.g., mixture) of pre-transformed (e.g., powder) materials, onepre-transformed material may be used as support (i.e., supportivepowder), as an insulator, as a cooling member (e.g., heat sink), or asany combination thereof. The cooling member can be any cooling memberdisclosed in 62/252,330, U.S. 62/317,070, 62/396,584, PCT/US15/36802, orPCT/US16/59781, all of which are entirely incorporated herein byreference.

In some instances, adjacent components in the material bed are separatedfrom one another by one or more intervening layers. In an example, afirst layer is adjacent to a second layer when the first layer is indirect contact with the second layer. In another example, a first layeris adjacent to a second layer when the first layer is separated from thesecond layer by at least one layer (e.g., a third layer). Theintervening layer may be of any layer size disclosed herein.

At times, the pre-transformed material is chosen such that the materialis the desired and/or otherwise predetermined material for the 3Dobject. In some cases, a layer of the 3D object comprises a single typeof material. For example, a layer of the 3D object can comprise a singleelemental metal type, or a single metal alloy type. In some examples, alayer within the 3D object may comprise several types of material (e.g.,an elemental metal and an alloy, an alloy and a ceramic, an alloy and anallotrope of elemental carbon). In certain embodiments, each type ofmaterial comprises only a single member of that type. For example: asingle member of elemental metal (e.g., iron), a single member of metalalloy (e.g., stainless steel), a single member of ceramic material(e.g., silicon carbide or tungsten carbide), or a single member (e.g.,an allotrope) of elemental carbon (e.g., graphite). In some cases, alayer of the 3D object comprises more than one type of material. In somecases, a layer of the 3D object comprises more than one member of amaterial type.

The elemental metal can be an alkali metal, an alkaline earth metal, atransition metal, a rare-earth element metal, or another metal. Thealkali metal can be Lithium, Sodium, Potassium, Rubidium, Cesium, orFrancium. The alkali earth metal can be Beryllium, Magnesium, Calcium,Strontium, Barium, or Radium. The transition metal can be Scandium,Titanium, Vanadium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper,Zinc, Yttrium, Zirconium, Platinum, Gold, Rutherfordium, Dubnium,Seaborgium, Bohrium, Hassium, Meitnerium, Ununbium, Niobium, Iridium,Molybdenum, Technetium, Ruthenium, Rhodium, Palladium, Silver, Cadmium,Hafnium, Tantalum, Tungsten, Rhenium, or Osmium. The transition metalcan be mercury. The rare-earth metal can be a lanthanide, or anactinide. The lanthanide metal can be Lanthanum, Cerium, Praseodymium,Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium,Dysprosium, Holmium, Erbium, Thulium, Ytterbium, or Lutetium. Theactinide metal can be Actinium, Thorium, Protactinium, Uranium,Neptunium, Plutonium, Americium, Curium, Berkelium, Californium,Einsteinium, Fermium, Mendelevium, Nobelium, or Lawrencium. The othermetal can be Aluminum, Gallium, Indium, Tin, Thallium, Lead, or Bismuth.

The metal alloy can be an iron based alloy, nickel based alloy, cobaltbased alloy, chrome based alloy, cobalt chrome based alloy, titaniumbased alloy, magnesium based alloy, copper based alloy, or anycombination thereof. The alloy may comprise an oxidation or corrosionresistant alloy. The alloy may comprise a super alloy (e.g., Inconel).The super alloy may comprise Inconel 600, 617, 625, 690, 718, or X-750.The metal (e.g., alloy or elemental) may comprise an alloy used forapplications in industries comprising aerospace (e.g., aerospace superalloys), jet engine, missile, automotive, marine, locomotive, satellite,defense, oil & gas, energy generation, semiconductor, fashion,construction, agriculture, printing, or medical. The metal (e.g., alloyor elemental) may comprise an alloy used for products comprising,devices, medical devices (human & veterinary), machinery, cell phones,semiconductor equipment, generators, engines, pistons, electronics(e.g., circuits), electronic equipment, agriculture equipment, motor,gear, transmission, communication equipment, computing equipment (e.g.,laptop, cell phone, i-pad), air conditioning, generators, furniture,musical equipment, art, jewelry, cooking equipment, or sport gear. Themetal (e.g., alloy or elemental) may comprise an alloy used for productsfor human or veterinary applications comprising implants, orprosthetics. The metal alloy may comprise an alloy used for applicationsin the fields comprising human or veterinary surgery, implants (e.g.,dental), or prosthetics.

The alloy may include a superalloy. The alloy may include ahigh-performance alloy. The alloy may include an alloy exhibiting atleast one of excellent mechanical strength, resistance to thermal creepdeformation, good surface stability, resistance to corrosion, andresistance to oxidation. The alloy may include a face-centered cubicaustenitic crystal structure. The alloy may comprise Hastelloy, Inconel,Waspaloy, Rene alloy (e.g., Rene-80, Rene-77, Rene-220, or Rene-41),Haynes alloy (e.g., Haynes 282), Incoloy, MP98T, TMS alloy, MTEK (e.g.,MTEK grade MAR-M-247, MAR-M-509, MAR-M-R41, or MAR-M-X-45), or CMSX(e.g., CMSX-3, or CMSX-4). The alloy can be a single crystal alloy.

In some instances, the iron alloy comprises Elinvar, Fernico,Ferroalloys, Invar, Iron hydride, Kovar, Spiegeleisen, Staballoy(stainless steel), or Steel. In some instances, the metal alloy issteel. The Ferroalloy may comprise Ferroboron, Ferrocerium, Ferrochrome,Ferromagnesium, Ferromanganese, Ferromolybdenum, Ferronickel,Ferrophosphorus, Ferrosilicon, Ferrotitanium, Ferrouranium, orFerrovanadium. The iron alloy may include cast iron, or pig iron. Thesteel may include Bulat steel, Chromoly, Crucible steel, Damascus steel,Hadfield steel, High speed steel, HSLA steel, Maraging steel (e.g.,M300), Reynolds 531, Silicon steel, Spring steel, Stainless steel, Toolsteel, Weathering steel, or Wootz steel. The high-speed steel mayinclude Mushet steel. The stainless steel may include AL-6XN, Alloy 20,celestrium, marine grade stainless, Martensitic stainless steel,surgical stainless steel, or Zeron 100. The tool steel may includeSilver steel. The steel may comprise stainless steel, Nickel steel,Nickel-chromium steel, Molybdenum steel, Chromium steel,Chromium-vanadium steel, Tungsten steel, Nickel-chromium-molybdenumsteel, or Silicon-manganese steel. The steel may be comprised of anySociety of Automotive Engineers (SAE) grade such as 440F, 410, 312, 430,440A, 440B, 440C, 304, 305, 304L, 304L, 301, 304LN, 301LN, 2304, 316,316L, 316LN, 317L, 2205, 409, 904L, 321, 254SMO, 316Ti, 321H, 17-4,15-5, 420, or 304H. The steel may comprise stainless steel of at leastone crystalline structure selected from the group consisting ofaustenitic, superaustenitic, ferritic, martensitic, duplex, andprecipitation-hardening martensitic. Duplex stainless steel may be leanduplex, standard duplex, super duplex, or hyper duplex. The stainlesssteel may comprise surgical grade stainless steel (e.g., austenitic 316,martensitic 420, or martensitic 440). The austenitic 316 stainless steelmay include 316LVM. The steel may include 17-4 Precipitation Hardeningsteel (also known as type 630, a chromium-copper precipitation hardeningstainless steel, 17-4PH steel).

The titanium-based alloys may include alpha alloys, near alpha alloys,alpha and beta alloys, or beta alloys. The titanium alloy may comprisegrade 1, 2, 2H, 3, 4, 5, 6, 7, 7H, 8, 9, 10, 11, 12, 13, 14, 15, 16,16H, 17, 18, 19, 20, 21, 2, 23, 24, 25, 26, 26H, 27, 28, 29, 30, 31, 32,33, 34, 35, 36, 37, 38, or higher. In some instances, the titanium basealloy includes Ti-6Al-4V or Ti-6Al-7Nb.

The Nickel alloy may include Alnico, Alumel, Chromel, Cupronickel,Ferronickel, German silver, Hastelloy, Inconel, Monel metal, Nichrome,Nickel-carbon, Nicrosil, Nisil, Nitinol, Hastelloy-X, Cobalt-Chromium,or Magnetically “soft” alloys. The magnetically “soft” alloys maycomprise Mu-metal, Permalloy, Supermalloy, or Brass. The brass mayinclude Nickel hydride, Stainless or Coin silver. The cobalt alloy mayinclude Megallium, Stellite (e. g. Talonite), Ultimet, or Vitallium. Thechromium alloy may include chromium hydroxide, or Nichrome.

The aluminum alloy may include AA-8000, Al—Li (aluminum-lithium),Alnico, Duralumin, Hiduminium, Kryron Magnalium, Nambe,Scandium-aluminum, or Y alloy. The magnesium alloy may be Elektron,Magnox, or T-Mg—Al—Zn (Bergman phase) alloy.

The copper alloy may comprise Arsenical copper, Beryllium copper,Billon, Brass, Bronze, Constantan, Copper hydride, Copper-tungsten,Corinthian bronze, Cunife, Cupronickel, Cymbal alloys, Devarda's alloy,Electrum, Hepatizon, Heusler alloy, Manganin, Molybdochalkos, Nickelsilver, Nordic gold, Shakudo, or Tumbaga. The Brass may include Calaminebrass, Chinese silver, Dutch metal, Gilding metal, Muntz metal,Pinchbeck, Prince's metal, or Tombac. The Bronze may include Aluminumbronze, Arsenical bronze, Bell metal, Florentine bronze, Guanin,Gunmetal, Glucydur, Phosphor bronze, Ormolu, or Speculum metal. Thecopper alloy may be a high-temperature copper alloy (e.g., GRCop-84).

In some examples, the material (e.g., powder material) comprises amaterial wherein its constituents (e.g., atoms or molecules) readilylose their outer shell electrons, resulting in a free-flowing cloud ofelectrons within their otherwise solid arrangement. In some examples,the material is characterized in having high electrical conductivity,low electrical resistivity, high thermal conductivity, or high density(e.g., as measured at ambient temperature (e.g., R.T., or 20° C.)). Thehigh electrical conductivity can be at least about 1*10⁵ Siemens permeter (S/m), 5*10⁵ S/m, 1*10⁶ S/m, 5*10⁶ S/m, 1*10⁷ S/m, 5*10⁷ S/m, or1*10⁸ S/m. The symbol “*” designates the mathematical operation “times,”or “multiplied by.” The high electrical conductivity can be any valuebetween the afore-mentioned electrical conductivity values (e.g., fromabout 1*10⁵ S/m to about 1*10⁸ S/m). The low electrical resistivity maybe at most about 1*10⁻⁵ ohm times meter (Ω*m), 5*10⁻⁶ Ω*m, 1*10⁻⁶ Ω*m,5*10⁻⁷ Ω*m, 1*10⁻⁷ Ω*m, 5*10⁻⁸, or 1*10⁻⁸ Ω*m. The low electricalresistivity can be any value between the afore-mentioned electricalresistivity values (e.g., from about 1×10⁻⁵ Ω*m to about 1×10⁻⁸ Ω*m).The high thermal conductivity may be at least about 20 Watts per meterstimes degrees Kelvin (W/mK), 50 W/mK, 100 W/mK, 150 W/mK, 200 W/mK, 205W/mK, 300 W/mK, 350 W/mK, 400 W/mK, 450 W/mK, 500 W/mK, 550 W/mK, 600W/mK, 700 W/mK, 800 W/mK, 900 W/mK, or 1000 W/mK. The high thermalconductivity can be any value between the afore-mentioned thermalconductivity values (e.g., from about 20 W/mK to about 1000 W/mK). Thehigh density may be at least about 1.5 grams per cubic centimeter(g/cm³), 2 g/cm³, 3 g/cm³, 4 g/cm³, 5 g/cm³, 6 g/cm³, 7 g/cm³, 8 g/cm³,9 g/cm³, 10 g/cm³, 11 g/cm³, 12 g/cm³, 13 g/cm³, 14 g/cm³, 15 g/cm³, 16g/cm³, 17 g/cm³, 18 g/cm³, 19 g/cm³, 20 g/cm³, or 25 g/cm³. The highdensity can be any value between the afore-mentioned density values(e.g., from about 1 g/cm³ to about 25 g/cm³).

In some examples, a metallic material (e.g., elemental metal or metalalloy) comprises small amounts of non-metallic materials, such as, forexample, oxygen, sulfur, or nitrogen. In some cases, the metallicmaterial comprises the non-metallic material in a trace amount. A traceamount can be at most about 100000 parts per million (ppm), 10000 ppm,1000 ppm, 500 ppm, 400 ppm, 200 ppm, 100 ppm, 50 ppm, 10 ppm, 5 ppm, or1 ppm (based on weight, w/w) of non-metallic material. A trace amountcan comprise at least about 10 ppt, 100 ppt, 1 ppb, 5 ppb, 10 ppb, 50ppb, 100 ppb, 200 ppb, 400 ppb, 500 ppb, 1000 ppb, 1 ppm, 10 ppm, 100ppm, 500 ppm, 1000 ppm, or 10000 ppm (based on weight, w/w) ofnon-metallic material. A trace amount can be any value between theafore-mentioned trace amounts (e.g., from about 10 parts per trillion(ppt) to about 100000 ppm, from about 1 ppb to about 100000 ppm, fromabout 1 ppm to about 10000 ppm, or from about 1 ppb to about 1000 ppm).

The one or more layers within the 3D object may be substantially planar(e.g., flat). The planarity of the layer may be substantially uniform.The height of the layer at a particular position may be compared to anaverage plane. The average plane may be defined by a least squaresplanar fit of the top-most part of the surface of the layer of hardenedmaterial. The average plane may be a plane calculated by averaging thematerial height at each point on the top surface of the layer ofhardened material. The deviation from any point at the surface of theplanar layer of hardened material may be at most 20% 15%, 10%, 5%, 3%,1%, or 0.5% of the height (e.g., thickness) of the layer of hardenedmaterial. The substantially planar one or more layers may have a largeradius of curvature. FIG. 17 shows an example of a vertical crosssection of a 3D object 1712 comprising planar layers (layers numbers1-4) and non-planar layers (e.g., layers numbers 5-6) that have a radiusof curvature. FIGS. 17, 1716 and 1717 are super-positions of curvedlayer on a circle 1715 having a radius of curvature “r.” The one or morelayers may have a radius of curvature equal to the radius of curvatureof the layer surface. The radius of curvature may equal infinity (e.g.,when the layer is planar). The radius of curvature of the layer surface(e.g., all the layers of the 3D object) may have a value of at leastabout 0.1 centimeter (cm), 0.2 cm, 0.3 cm, 0.4 cm, 0.5 cm, 0.6 cm, 0.7cm, 0.8 cm, 0.9 cm, 1 cm, 5 cm, 10 cm, 20 cm, 30 cm, 40 cm, 50 cm, 60cm, 70 cm, 80 cm, 90 cm, 1 meter (m), 1.5 m, 2 m, 2.5 m, 3 m, 3.5 m, 4m, 4.5 m, 5 m, 10 m, 15 m, 20 m, 25 m, 30 m, 50 m, or 100 m. The radiusof curvature of the layer surface (e.g., all the layers of the 3Dobject) may have any value between any of the afore-mentioned values ofthe radius of curvature (e.g., from about 10 cm to about 90 m, fromabout 50 cm to about 10 m, from about 5 cm to about 1 m, from about 50cm to about 5 m, from about 5 cm to infinity, or from about 40 cm toabout 50 m). In some embodiments, a layer with an infinite radius ofcurvature is a layer that is planar. In some examples, the one or morelayers may be included in a planar section of the 3D object, or may be aplanar 3D object (e.g., a flat plane). In some instances, part of atleast one layer within the 3D object has the radius of curvaturementioned herein.

In some examples, the 3D object comprises a layering plane N of thelayered 3D structure. The 3D object may comprise points X and Y, whichreside on the surface of the 3D object, wherein X is spaced apart from Yby at least about 10.5 millimeters or more. FIG. 18 shows an example ofpoints X and Y on the surface of a 3D object. In some embodiments, X isspaced apart from Y by the auxiliary support feature spacing distancedisclosed herein. In some examples, a sphere of radius XY that iscentered at X lacks one or more auxiliary supports or one or moreauxiliary support marks that are indicative of a presence or removal ofthe one or more auxiliary support features. In some embodiments, Y isspaced apart from X by at least about 10.5 millimeters or more. In someexamples, an acute angle between the straight line XY and the directionnormal to N may be from about 45 degrees to about 90 degrees. The acuteangle between the straight line XY and the direction normal to thelayering plane may be of the value of the acute angle alpha disclosedherein. When the angle between the straight line XY and the direction ofnormal to N is greater than 90 degrees, one considers the complementaryacute angle. The layer structure may comprise any material(s) used for3D printing described herein. Each layer of the 3D structure can be madeof a single material or of multiple materials. Sometimes one part of thelayer may comprise one material, and another part may comprise a secondmaterial different than the first material. A layer of the 3D object maybe composed of a composite material. The 3D object may be composed of acomposite material. The 3D object may comprise a functionally gradedmaterial.

In some embodiments, the generated 3D object is generated with theaccuracy of at least about 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85μm, 90 μm, 95 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 400 μm, 500μm, 600 μm, 700 μm, 800 μm, 900 μm, 1000 μm, 1100 μm, or 1500 μm ascompared to a model of the 3D object (e.g., the requested 3D object). Insome embodiments, the generated 3D object is generated with the accuracyof at most about 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm,45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700μm, 800 μm, 900 μm, 1000 μm, 1100 μm, or 1500 μm as compared to a modelof the 3D object. As compared to a model of the 3D object, the generated3D object may be generated with the accuracy of any accuracy valuebetween the afore-mentioned values (e.g., from about 5 μm to about 100μm, from about 15 μm to about 35 μm, from about 100 μm to about 1500 μm,from about 5 μm to about 1500 μm, or from about 400 μm to about 600 μm).

In some situations, the hardened layer of transformed material deforms(e.g., during and/or after the 3D printing). For example, thedeformation causes a height deviation from a uniformly planar layer ofhardened material. The height uniformity (e.g., deviation from averagesurface height) of the planar surface of the layer of hardened materialmay be at least about 100 μm, 90 μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm,30 μm, 20 μm, 10 μm, or 5 μm. The height uniformity of the planarsurface of the layer of hardened material may be at most about 100 μm,90 μm, 80, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, 10 μm, or 5 μm. Theheight uniformity of the planar surface of the layer of hardenedmaterial may be any value between the afore-mentioned height deviationvalues (e.g., from about 100 μm to about 5 μm, from about 50 μm to about5 μm, from about 30 μm to about 5 μm, or from about 20 μm to about 5μm). For example, the height uniformity be included in a high precisionuniformity of the 3D printing. In some embodiments, the resolution ofthe 3D object is at least about 100 dots per inch (dpi), 300 dpi, 600dpi, 1200 dpi, 2400 dpi, 3600 dpi, or 4800 dpi. In some embodiments, theresolution of the 3D object is at most about 100 dpi, 300 dpi, 600 dpi,1200 dpi, 2400 dpi, 3600 dpi, or 4800 dpi. The resolution of the 3Dobject may be any value between the afore-mentioned values (e.g., from100 dpi to 4800 dpi, from 300 dpi to 2400 dpi, or from 600 dpi to 4800dpi).

In some embodiments, the height uniformity of a layer of hardenedmaterial persists across a portion of the layer surface that has a widthor a length of at least about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, or 10 mm,have a height deviation of at least about 10 mm, 9 mm, 8 mm, 7 mm, 6 mm,5 mm, 4 mm, 3 mm, 2 mm, 1 mm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, 90μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, or 10 μm. In someembodiments, the height uniformity of a layer of hardened materialpersists across a portion of the target surface that has a width or alength of most about 10 mm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2mm, 1 mm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, 90 μm, 80, 70 μm, 60μm, 50 μm, 40 μm, 30 μm, 20 μm, or 10 μm. The height uniformity of alayer of hardened material may persist across a portion of the targetsurface that has a width or a length of or of any value between theafore-mentioned width or length values (e.g., from about 10 mm to about10 μm, from about 10 mm to about 100 μm, or from about 5 mm to about 500μm).

Characteristics of the hardened material and/or any of its parts (e.g.,layer of hardened material) can be measured by any of the followingmeasurement methodologies. For example, the FLS values (e.g., width),height uniformity, auxiliary support space, an/d or radius of curvatureof the layer of the 3D object and any of its components (e.g., layer ofhardened material) may be measured by any of the following measuringmethodologies. The FLS of opening ports may be measured by one or moreof following measurement methodologies. The measurement methodologiesmay comprise a microscopy method (e.g., any microscopy method describedherein). The measurement methodologies may comprise a coordinatemeasuring machine (CMM), measuring projector, vision measuring system,and/or a gauge. The gauge can be a gauge distometer (e.g., caliber). Thegauge can be a go-no-go gauge. The measurement methodologies maycomprise a caliber (e.g., vernier caliber), positive lens,interferometer, or laser (e.g., tracker). The measurement methodologiesmay comprise a contact or by a non-contact method. The measurementmethodologies may comprise one or more sensors (e.g., optical sensorsand/or metrological sensors). The measurement methodologies may comprisea metrological measurement device (e.g., using metrological sensor(s)).The measurements may comprise a motor encoder (e.g., rotary and/orlinear). The measurement methodologies may comprise using anelectromagnetic beam (e.g., visible or IR). The microscopy method maycomprise ultrasound or nuclear magnetic resonance. The microscopy methodmay comprise optical microscopy. The microscopy method may compriseelectromagnetic, electron, or proximal probe microscopy. The electronmicroscopy may comprise scanning, tunneling, X-ray photo-, or Augerelectron microscopy. The electromagnetic microscopy may compriseconfocal, stereoscope, or compound microscopy. The microscopy method maycomprise an inverted and/or non-inverted microscope. The proximal probemicroscopy may comprise atomic force, or scanning tunneling microscopy,or any other microscopy described herein. The microscopy measurementsmay comprise using an image analysis system. The measurements may beconducted at ambient temperatures (e.g., R.T.)

The microstructures (e.g., of melt pools) of the 3D object may bemeasured by a microscopy method (e.g., any microscopy method describedherein). The microstructures may be measured by a contact or by anon-contact method. The microstructures may be measured by using anelectromagnetic beam (e.g., visible or IR). The microstructuremeasurements may comprise evaluating the dendritic arm spacing and/orthe secondary dendritic arm spacing (e.g., using microscopy). Themicroscopy measurements may comprise using an image analysis system. Themeasurements may be conducted at ambient temperatures (e.g., R.T.).

Various distances relating to the chamber can be measured using any ofthe following measurement techniques. Various distances within thechamber can be measured using any of the following measurementtechniques. For example, the gap distance (e.g., from the cooling memberto the exposed surface of the material bed) may be measured using any ofthe following measurement techniques. The measurements techniques maycomprise interferometry and/or confocal chromatic measurements. Themeasurements techniques may comprise at least one motor encoder (rotary,linear). The measurement techniques may comprise one or more sensors(e.g., optical sensors and/or metrological sensors). The measurementtechniques may comprise at least one inductive sensor. The measurementtechniques may include an electromagnetic beam (e.g., visible or IR).The measurements may be conducted at ambient temperature (e.g., R.T.).

The methods described herein can provide surface uniformity across theexposed surface of the material bed (e.g., top of a powder bed) suchthat portions of the exposed surface that comprises the dispensedmaterial, which are separated from one another by a distance of fromabout 1 mm to about 10 mm, have a height deviation from about 100 μm toabout 5 μm. The methods described herein may achieve a deviation from aplanar uniformity of the layer of pre-transformed material (e.g.,powder) in at least one plane (e.g., horizontal plane) of at most about20%, 10%, 5%, 2%, 1% or 0.5%, as compared to the average plane (e.g.,horizontal plane) created at the exposed surface of the material bed(e.g., top of a powder bed). The height deviation can be measured byusing one or more sensors (e.g., optical sensors).

The 3D object can have various surface roughness profiles, which may besuitable for various applications. The surface roughness may be thedeviations in the direction of the normal vector of a real surface, fromits ideal form. The surface roughness may be measured as the arithmeticaverage of the roughness profile (hereinafter “Ra”). In some examples,the formed 3D object can have a Ra value of at most about 300 μm, 200μm, 100 μm, 75 μm, 50 μm, 45 μm, 40 μm, 35 μm, 30 μm, 25 μm, 20 μm, 15μm, 10 μm, 7 μm, or 5 μm. The 3D object can have a Ra value between anyof the afore-mentioned Ra values (e.g., from about 300 μm to about 5 μm,from about 300 μm to about 40 μm, from about 100 μm to about 5 μm, orfrom about 100 μm to about 20 μm). The Ra values may be measured by acontact or by a non-contact method. The Ra values may be measured by aroughness tester and/or by a microscopy method (e.g., any microscopymethod described herein). The measurements may be conducted at ambienttemperatures (e.g., R.T.). The roughness may be measured by a contact orby a non-contact method. The roughness measurement may comprise one ormore sensors (e.g., optical sensors). The roughness measurement maycomprise a metrological measurement device (e.g., using metrologicalsensor(s)). The roughness may be measured using an electromagnetic beam(e.g., visible or IR).

The 3D object may be composed of successive layers (e.g., successivecross sections) of solid material that originated from a transformedmaterial (e.g., fused, sintered, melted, bound or otherwise connectedpowder material), and subsequently hardened. The transformedpre-transformed material may be connected to a hardened (e.g.,solidified) material as part of its transformation. The hardenedmaterial may reside within the same layer, or in another layer (e.g., apreviously formed layer of hardened material). In some examples, thehardened material comprises disconnected parts of the 3D object, thatare subsequently connected by the newly transformed material (e.g., byfusing, sintering, melting, binding or otherwise connecting apre-transformed material).

A cross section (e.g., vertical cross section) of the generated (i.e.,formed) 3D object may reveal a microstructure or a grain structureindicative of a layered deposition. Without wishing to be bound totheory, the microstructure or grain structure may arise due to thesolidification of transformed powder material that is typical to and/orindicative of the 3D printing method. For example, a cross section mayreveal a microstructure resembling ripples or waves that are indicativeof solidified melt pools that may be formed during the 3D printingprocess. The repetitive layered structure of the solidified melt poolsmay reveal the orientation at which the part was printed. The crosssection may reveal a substantially repetitive microstructure or grainstructure. The microstructure or grain structure may comprisesubstantially repetitive variations in material composition, grainorientation, material density, degree of compound segregation or ofelement segregation to grain boundaries, material phase, metallurgicalphase, crystal phase, crystal structure, material porosity, or anycombination thereof. The microstructure or grain structure may comprisesubstantially repetitive solidification of layered melt pools. The layerof hardened material may have an average layer height of at least about0.5 μm, 1 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80μm, 90 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450μm, or 500 μm. The layer of hardened material may have an average layerheight of at most about 500 μm, 450 μm, 400 μm, 350 μm, 300 μm, 250 μm,200 μm, 150 μm, 100 μm, 90 μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm,20 μm, or 10 μm. The layer of hardened material may have an averagelayer height of any value between the afore-mentioned values of layerheights (e.g., from about 0.5 μm to about 500 μm, from about 15 μm toabout 50 μm, from about 5 μm to about 150 μm, from about 20 μm to about100 μm, or from about 10 μm to about 80 μm).

The pre-transformed material within the material bed (e.g., powder) canbe configured to provide support to the 3D object. For example, thesupportive pre-transformed may be of the same type of pre-transformedmaterial from which the 3D object is generated, of a different type, orany combination thereof. In some instances, a low flowabilitypre-transformed material (e.g., powder) can support a 3D object betterthan a high flowability pre-transformed material. A low flowabilitypre-transformed material can be achieved inter alia with a particulatematerial composed of relatively small particles, with particles ofnon-uniform size or with particles that attract each other. Thepre-transformed material may be of low, medium, or high flowability. Thepre-transformed material may have compressibility of at least about 1%,2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% in response to an applied forceof 15 kilo Pascals (kPa). The pre-transformed material may have acompressibility of at most about 9%, 8%, 7%, 6%, 5%, 4.5%, 4.0%, 3.5%,3.0%, 2.5%, 2.0%, 1.5%, 1.0%, or 0.5% in response to an applied force of15 kilo Pascals (kPa). The pre-transformed material may have basic flowenergy of at least about 100 milli-Joule (mJ), 200 mJ, 300 mJ, 400 mJ,450 mJ, 500 mJ, 550 mJ, 600 mJ, 650 mJ, 700 mJ, 750 mJ, 800 mJ, or 900mJ. The pre-transformed material may have basic flow energy of at mostabout 200 mJ, 300 mJ, 400 mJ, 450 mJ, 500 mJ, 550 mJ, 600 mJ, 650 mJ,700 mJ, 750 mJ, 800 mJ, 900 mJ, or 1000 mJ. The pre-transformed materialmay have basic flow energy in between the above listed values of basicflow energy (e.g., from about 100 mj to about 1000 mJ, from about 100 mjto about 600 mJ, or from about 500 mj to about 1000 mJ). Thepre-transformed material may have a specific energy of at least about1.0 milli-Joule per gram (mJ/g), 1.5 mJ/g, 2.0 mJ/g, 2.5 mJ/g, 3.0 mJ/g,3.5 mJ/g, 4.0 mJ/g, 4.5 mJ/g, or 5.0 mJ/g. The pre-transformed materialmay have a specific energy of at most 5.0 mJ/g, 4.5 mJ/g, 4.0 mJ/g, 3.5mJ/g, 3.0 mJ/g, 2.5 mJ/g, 2.0 mJ/g, 1.5 mJ/g, or 1.0 mJ/g. The powdermay have a specific energy in between any of the above values ofspecific energy (e.g., from about 1.0 mJ/g to about 5.0 mJ/g, from about3.0 mJ/g to about 5 mJ/g, or from about 1.0 mJ/g to about 3.5 mJ/g).

In some embodiments, the 3D object includes one or more auxiliaryfeatures. The auxiliary feature(s) can be supported by the material(e.g., powder) bed. The term “auxiliary features,” as used herein,generally refers to features that are part of a printed 3D object, butare not part of the desired, intended, designed, ordered, modeled, orfinal 3D object. Auxiliary features (e.g., auxiliary supports) mayprovide structural support during and/or after the formation of the 3Dobject. Auxiliary features may enable the removal or energy from the 3Dobject that is being formed. Examples of auxiliary features compriseheat fins, wires, anchors, handles, supports, pillars, columns, frame,footing, scaffold, flange, projection, protrusion, mold (a.k.a. mould),or other stabilization features. In some instances, the auxiliarysupport is a scaffold that encloses the 3D object or part thereof. Thescaffold may comprise lightly sintered or lightly fused powder material.The 3D object can have auxiliary features that can be supported by thematerial bed (e.g., powder bed) and not touch the base, substrate,container accommodating the material bed, or the bottom of theenclosure. The 3D part (3D object) in a complete or partially formedstate can be completely supported by the material bed (e.g., suspendedanchorlessly in the material bed without touching the substrate, base,container accommodating the material bed, or the enclosure). The 3Dobject in a complete or partially formed state can be completelysupported by the material bed (e.g., without touching anything exceptthe material bed). The 3D object in a complete or partially formed statecan be suspended in the material bed without resting on any additionalsupport structures. In some cases, the 3D object in a complete orpartially formed (i.e., nascent) state can freely float (e.g.,anchorless) in the material bed. In some examples, the 3D object may notbe anchored (e.g., connected) to the platform and/or walls that definethe material bed (e.g., during formation). The 3D object may not touch(e.g., contact) to the platform and/or walls that define the materialbed (e.g., during formation). The 3D object be suspended (e.g., float)anchorlessly in the material bed. The scaffold may comprise acontinuously sintered (e.g., lightly sintered) structure that is at most1 millimeter (mm), 2 mm, 5 mm or 10 mm. The scaffold may comprise acontinuously sintered structure that is at least 1 millimeter (mm), 2mm, 5 mm or 10 mm. The scaffold may comprise a continuously sinteredstructure having dimensions between any of the afore-mentioneddimensions (e.g., from about 1 mm to about 10 mm, or from about 1 mm toabout 5 mm). In some examples, the 3D object may be printed without asupporting scaffold. The supporting scaffold may engulf the 3D object.The supporting scaffold may float anchorlessly in the material bed. Thescaffold may comprise a lightly sintered structure.

In some embodiments, the printed 3D object is printed (i) without theuse of auxiliary supports, (ii) using a reduced amount of auxiliarysupports, or (iii) using spaced apart auxiliary supports. In someembodiments, the printed 3D object may be devoid of one or moreauxiliary supports or auxiliary support marks that are indicative of apresence or removal of the auxiliary support features. The 3D object maybe devoid of one or more auxiliary supports and of one or more marks ofan auxiliary feature (including a base structure) that were removed(e.g., subsequent to, or contemporaneous with, the generation of the 3Dobject). In some embodiments, the printed 3D object comprises a singleauxiliary support mark. The single auxiliary feature (e.g., auxiliarysupport or auxiliary structure) may be a platform (e.g., a buildingplatform such as a base or substrate), or a mold. The auxiliary supportmay be adhered (e.g., and anchored) to the platform or mold. The 3Dobject may comprise marks belonging to one or more auxiliary structures.The 3D object may comprise two or more marks belonging to auxiliaryfeatures. The 3D object may be devoid of marks pertaining to anauxiliary support. The 3D object may be devoid of auxiliary support. Themark may comprise variation in grain orientation, variation in layeringorientation, layering thickness, material density, the degree ofcompound segregation to grain boundaries, material porosity, the degreeof element segregation to grain boundaries, material phase,metallurgical phase, crystal phase, or crystal structure; wherein thevariation may not have been created by the geometry of the 3D objectalone, and may thus be indicative of a prior existing auxiliary supportthat was removed. The variation may be forced upon the generated 3Dobject by the geometry of the support. In some instances, the 3Dstructure of the printed object may be forced by the auxiliary support(e.g., by a mold). For example, a mark may be a point of discontinuity(e.g., formed due to a cut or trimming) that is not explained by thegeometry of the 3D object, which does not include any auxiliarysupports. A mark may be a surface feature that cannot be explained bythe geometry of a 3D object, which does not include any auxiliarysupports (e.g., a mold). The two or more auxiliary features or auxiliarysupport feature marks may be spaced apart by a spacing distance of atleast 1.5 millimeters (mm), 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5mm, 15 mm, 15.5 mm, 16 mm, 20 mm, 20.5 mm, 21 mm, 25 mm, 30 mm, 30.5 mm,31 mm, 35 mm, 40 mm, 40.5 mm, 41 mm, 45 mm, 50 mm, 80 mm, 100 mm, 200 mm300 mm, or 500 mm. The two or more auxiliary support features orauxiliary support feature marks may be spaced apart by a spacingdistance of at most 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5mm, 15 mm, 15.5 mm, 16 mm, 20 mm, 20.5 mm, 21 mm, 25 mm, 30 mm, 30.5 mm,31 mm, 35 mm, 40 mm, 40.5 mm, 41 mm, 45 mm, 50 mm, 80 mm, 100 mm, 200 mm300 mm, or 500 mm. The two or more auxiliary support features orauxiliary support feature marks may be spaced apart by a spacingdistance of any value between the afore-mentioned auxiliary supportspace values (e.g., from 1.5 mm to 500 mm, from 2 mm to 100 mm, from 15mm to 50 mm, or from 45 mm to 200 mm). Collectively referred to hereinas the “auxiliary support feature spacing distance.”

The 3D object may comprise a layered structure indicative of 3D printingprocess that is devoid of one or more auxiliary support features or oneor more auxiliary support feature marks that are indicative of apresence or removal of the one or more auxiliary support features. The3D object may comprise a layered structure indicative of 3D printingprocess, which includes one, two, or more auxiliary support marks. Thesupports or support marks can be on the surface of the 3D object. Theauxiliary supports or support marks can be on an external, on aninternal surface (e.g., a cavity within the 3D object), or both. Thelayered structure can have a layering plane. In one example, twoauxiliary support features or auxiliary support feature marks present inthe 3D object may be spaced apart by the auxiliary feature spacingdistance. The acute (i.e., sharp) angle alpha between the straight lineconnecting the two auxiliary supports or auxiliary support marks and thedirection of normal to the layering plane may be at least about 45degrees(°), 50°, 55°, 60°, 65°, 70°, 75°, 80°, or 85°. The acute anglealpha between the straight line connecting the two auxiliary supports orauxiliary support marks and the direction of normal to the layeringplane may be at most about 90°, 85°, 80°, 75°, 70°, 65°, 60°, 55°, 50°,or 45°. The acute angle alpha between the straight line connecting thetwo auxiliary supports or auxiliary support marks and the direction ofnormal to the layering plane may be any angle range between theafore-mentioned angles (e.g., from about 45 degrees(°), to about 90°,from about 60° to about 90°, from about 75° to about 90°, from about 80°to about 90°, from about 85° to about 90°). The acute angle alphabetween the straight line connecting the two auxiliary supports orauxiliary support marks and the direction normal to the layering planemay from about 87° to about 90°. An example of a layering plane can beseen in FIG. 17 showing a vertical cross section of a 3D object 1711that comprises layers 1 to 6, each of which are planar. In the schematicexample in FIG. 17, the layering plane of the layers can be the layer.For example, layer 1 could correspond to both the layer and the layeringplane of layer 1. When the layer is not planar (e.g., FIG. 17, layer 5of 3D object 1712), the layering plane would be the average plane of thelayer. The two auxiliary supports or auxiliary support feature marks canbe on the same surface. The same surface can be an external surface oran internal surface (e.g., a surface of a cavity within the 3D object).When the angle between the shortest straight line connecting the twoauxiliary supports or auxiliary support marks and the direction ofnormal to the layering plane is greater than 90 degrees, one canconsider the complementary acute angle. In some embodiments, any twoauxiliary supports or auxiliary support marks are spaced apart by theauxiliary feature spacing distance.

FIG. 20C shows an example of a 3D object comprising an exposed surface2001 that was formed with layers of hardened material (e.g., havinglayering plane 2005) that are substantially planar and parallel to theplatform 2003. FIG. 20C shows an example of a 3D object comprising anexposed surface 2002 that was formed with layers of hardened material(e.g., having layering plane 2006) that are substantially planar andparallel to the platform 2003 resulting in a tilted 3D object (e.g.,box). The 3D object that was formed as a tiled 3D object during itsformation, is shown lying flat on a surface 2009 as a 3D object havingan exposed surface 2004 and layers of hardened material (e.g., havinglayering plane 2007) having a normal 2008 to the layering plane thatforms acute angle alpha with the exposed surface 2004 of the 3D object.FIGS. 20A and 20B show 3D objects comprising layers of solidified meltpools that are arranged in layers having layering planes (e.g., 2020).FIG. 19 shows a vertical cross section in a coordinate system. Line 1904represents a vertical cross section of the top surface of a platform.Line 1903 represents a normal to the average layering plane. Line 1902represent the normal to the top surface of the platform. Line 1901represents the direction of the gravitational field. The angle alpha inFIG. 19 is formed between the normal to the layering plane, and the topplatform surface.

In some instances, the one or more auxiliary features are specific to a3D object and can increase the time needed to generate the requested 3Dobject. The one or more auxiliary features can be removed prior to useor distribution of the requested 3D object. Eliminating the need forauxiliary features can decrease the time and cost associated withgenerating the three-dimensional part. In some examples, the diminishednumber of auxiliary supports or lack of one or more auxiliary support,will provide a 3D printing process that requires a smaller amount ofmaterial, produces a smaller amount of material waste, and/or requiressmaller energy as compared to commercially available 3D printingprocesses. The smaller amount can be smaller by at least about 1.1, 1.3,1.5, 2, 3, 4, 5, 6, 7, 8, 9, or 10. The smaller amount may be smaller byany value between the aforesaid values (e.g., from about 1.1 to about10, or from about 1.5 to about 5).

In some examples, the 3D object is formed with auxiliary features. Insome examples, the 3D object may be formed with contact (e.g., but notanchor) to the container accommodating the material bed (e.g., side(s)and/or bottom of the container). The longest dimension of across-section of an auxiliary feature can be at most about 50 nm, 100nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, or1000 nm, 1 μm, 3 μm, 10 μm, 20 μm, 30 μm, 100 μm, 200 μm, 300 μm, 400μm, 500 μm, 700 μm, 1 mm, 3 mm, 5 mm, 10 mm, 20 mm, 30 mm, 50 mm, 100mm, or 300 mm. The longest dimension of a cross-section of an auxiliaryfeature can be at least about 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500nm, 600 nm, 700 nm, 800 nm, 900 nm, or 1000 nm, 1 μm, 3 μm, 10 μm, 20μm, 30 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 700 μm, 1 mm, 3 mm, 5mm, 10 mm, 20 mm, 30 mm, 50 mm, 100 mm, or 300 mm. The longest dimensionof a cross-section of an auxiliary feature can be any value between theabove-mentioned values (e.g., from about 50 nm to about 300 mm, fromabout 5 μm to about 10 mm, from about 50 nm to about 10 mm, or fromabout 5 mm to about 300 mm).

At least a portion of the 3D object can sink in the material bed. Atleast a portion of the 3D object can be surrounded by pre-transformedmaterial within the material bed (e.g., submerged). At least a portionof the 3D object can rest in the pre-transformed material withoutsubstantial sinking (e.g., vertical movement). Lack of substantialsinking can amount to a sinking (e.g., vertical movement) of at mostabout 40%, 20%, 10%, 5%, or 1% layer thickness. Lack of substantialsinking can amount to at most about 100 μm, 30 μm, 10 μm, 3 μm, or 1 μm.At least a portion of the 3D object can rest in the pre-transformedmaterial without substantial movement (e.g., horizontal movement,movement at an angle). Lack of substantial movement can amount to atmost 100 μm, 30 μm, 10 μm, 3 μm, or 1 μm. The 3D object can rest on thesubstrate when the 3D object is sunk or submerged in the material bed.

FIG. 1 depicts an example of a system that can be used to generate a 3Dobject using a 3D printing process disclosed herein. The system caninclude an enclosure (e.g., 107). At least a fraction of the componentsin the system can be enclosed in the chamber. At least a fraction of thechamber can be filled with at least one gas to create a gaseousenvironment (i.e., an atmosphere). The gas can be an inert gas (e.g.,Argon, Neon, Helium, Nitrogen). The chamber can be filled with anothergas or mixture of gases. The gas can be a non-reactive gas (e.g., aninert gas). The gaseous environment can comprise argon, nitrogen,helium, neon, krypton, xenon, hydrogen, carbon monoxide, or carbondioxide. The gas can be an ultrahigh purity gas. For example, theultrahigh purity gas can be at least about 99%, 99.9%, 99.99%, or99.999% pure. The gas may comprise less than about 2 ppm oxygen, lessthan about 3 ppm moisture, less than about 1 ppm hydrocarbons, or lessthan about 6 ppm nitrogen. In some examples, the pressure in the chamberis at least about 10⁻⁷ Torr, 10⁻⁶ Torr, 10⁻⁵ Torr, 10⁻⁴ Torr, 10⁻³ Torr,10⁻² Torr, 10⁻¹ Torr, 1 Torr, 10 Torr, 100 Torr, 1 bar, 2 bar, 3 bar, 4bar, 5 bar, 10 bar, 20 bar, 30 bar, 40 bar, 50 bar, 100 bar, 200 bar,300 bar, 400 bar, 500 bar, 1000 bar, or more. In some examples, thepressure in the chamber is at least about 100 Torr, 200 Torr, 300 Torr,400 Torr, 500 Torr, 600 Torr, 700 Torr, 720 Torr, 740 Torr, 750 Torr,760 Torr, 900 Torr, 1000 Torr, 1100 Torr, or 1200 Torr. In someexamples, the pressure in the chamber is at most about 10⁻⁷ Torr, 10⁻⁶Torr, 10⁻⁵ Torr, or 10⁻⁴ Torr, 10⁻³ Torr, 10⁻² Torr, 10⁻¹ Torr, 1 Torr,10 Torr, 100 Torr, 200 Torr, 300 Torr, 400 Torr, 500 Torr, 600 Torr, 700Torr, 720 Torr, 740 Torr, 750 Torr, 760 Torr, 900 Torr, 1000 Torr, 1100Torr, or 1200 Torr. The pressure in the chamber can be at a rangebetween any of the afore-mentioned pressure values (e.g., from about10⁻⁷ Torr to about 1200 Torr, from about 10⁻⁷ Torr to about 1 Torr, fromabout 1 Torr to about 1200 Torr, or from about 10⁻² Torr to about 10Torr). The pressure can be measured by a pressure gauge. The pressurecan be measured at ambient temperature (e.g., R.T.). In some cases, thepressure in the chamber can be standard atmospheric pressure. In somecases, the pressure in the chamber can be ambient pressure (i.e.,surrounding pressure). In some examples, the chamber can be under vacuumpressure. In some examples, the chamber can be under a positive pressure(i.e., above ambient pressure). The pressure in the enclosure may be ata constant value at least during a portion of the 3D printing process(e.g., during the entire 3D printing). In some embodiments, the 3Dprinting takes place in a (e.g., substantially) constant pressure.Constant pressure excludes pressure gradients in the material bed duringthe 3D printing.

The concentration of oxygen and/or humidity in the enclosure (e.g.,chamber) can be minimized (e.g., below a predetermined threshold value).For example, the gas composition of the chamber can contain a level ofoxygen and/or humidity that is at most about 100 parts per billion(ppb), 10 ppb, 1 ppb, 0.1 ppb, 0.01 ppb, 0.001 ppb, 100 parts permillion (ppm), 10 ppm, 1 ppm, 0.1 ppm, 0.01 ppm, or 0.001 ppm. The gascomposition of the chamber can contain an oxygen and/or humidity levelbetween any of the afore-mentioned values (e.g., from about 100 ppb toabout 0.001 ppm, from about 1 ppb to about 0.01 ppm, or from about 1 ppmto about 0.1 ppm). The gas composition may be measures by one or moresensors (e.g., an oxygen and/or humidity sensor.). In some cases, thechamber can be opened at or after printing the 3D object. When thechamber is opened, ambient air containing oxygen and/or humidity canenter the chamber. Exposure of one or more components inside of thechamber to air can be reduced by, for example, flowing an inert gaswhile the chamber is open (e.g., to prevent entry of ambient air), or byflowing a heavy gas (e.g., argon) that rests on the surface of thepowder bed. In some cases, components that absorb oxygen and/or humidityon to their surface(s) can be sealed while the chamber is open. In someembodiments, the chamber is minimally exposed to the externalenvironment by usage of one or more load lock chambers. In the load lockchamber, the purging of gas may be done in a smaller gas volume ascompared to the chamber gas volume (e.g., 116).

The chamber can be configured such that gas inside of the chamber has arelatively low leak rate from the chamber to an environment outside ofthe chamber. In some cases, the leak rate can be at most about 100milliTorr/minute (mTorr/min), 50 mTorr/min, 25 mTorr/min, 15 mTorr/min,10 mTorr/min, 5 mTorr/min, 1 mTorr/min, 0.5 mTorr/min, 0.1 mTorr/min,0.05 mTorr/min, 0.01 mTorr/min, 0.005 mTorr/min, 0.001 mTorr/min, 0.0005mTorr/min, or 0.0001 mTorr/min. The leak rate may be between any of theafore-mentioned leak rates (e.g., from about 0.0001 mTorr/min to about,100 mTorr/min, from about 1 mTorr/min to about, 100 mTorr/min, or fromabout 1 mTorr/min to about, 100 mTorr/min). The leak rate may bemeasured by one or more pressure gauges and/or sensors (e.g., at ambienttemperature). The enclosure can be sealed such that the leak rate of gasfrom inside the chamber to an environment outside of the chamber is low(e.g., below a certain level). The seals can comprise O-rings, rubberseals, metal seals, load-locks, or bellows on a piston. In some cases,the chamber can have a controller configured to detect leaks above aspecified leak rate (e.g., by using at least one sensor). The sensor maybe coupled to a controller. In some instances, the controller identifiesand/or control (e.g., direct and/or regulate). For example, thecontroller may be able to identify a leak by detecting a decrease inpressure in side of the chamber over a given time interval.

In some examples, a pressure system is in fluid communication with theenclosure and/or material removal mechanism. The pressure system can beconfigured to regulate the pressure in the enclosure and/or materialremoval mechanism. In some examples, the pressure system includes one ormore vacuum pumps selected from mechanical pumps, rotary vain pumps,turbomolecular pumps, ion pumps, cryopumps, and diffusion pumps. Thevacuum pump may be any pump disclosed herein. The pressure system caninclude a pressure sensor for measuring the pressure and relaying thepressure to the controller, which can regulate the pressure with the aidof one or more vacuum pumps of the pressure system. The pressure sensorcan be operatively coupled to a control system. The pressure can beelectronically or manually controlled (during, before, or after the 3Dprinting). The pressure may be measured in the enclosure, and/or in thematerial removal mechanism. For example, the pressure can be measured(i) just outside the nozzle, (ii) in the internal reservoir, and/or(iii) in the nozzle of the material removal mechanism. The pressure canbe measured along the channel that couples the material removalmechanism to the force generator (e.g., pressure pump).

In some examples, the system and/or apparatus components describedherein are adapted and configured to generate a 3D object. The 3D objectcan be generated through a 3D printing process. A first layer ofmaterial can be provided adjacent to a platform. A base can be apreviously formed layer of the 3D object or any other surface upon whicha layer or bed of material is spread, held, placed, or supported. In thecase of formation of the first layer of the 3D object the first materiallayer can be formed in the material bed without a base, without one ormore auxiliary support features (e.g., rods), or without othersupporting structure other than the material (e.g., within the materialbed). Subsequent layers can be formed such that at least one portion ofthe subsequent layer melts, sinters, fuses, binds and/or otherwiseconnects to the at least a portion of a previously formed layer. In someinstances, the at least a portion of the previously formed layer that istransformed and subsequently hardens into a hardened material, acts as abase for formation of the 3D object. In some cases, the first layercomprises at least a portion of the base. The material of the materialcan be any material described herein. The material layer can compriseparticles of homogeneous or heterogeneous size and/or shape.

The system and/or apparatus described herein may comprise at least oneenergy source (e.g., the scanning energy source generating the firstscanning energy, second scanning energy. E.g., the tiling energy sourcegenerating the tiling energy flux). In some cases, the system cancomprise 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 30, 100, 300, 1000 or moreenergy fluxes (e.g., beams) and/or sources. The system can comprise anarray of energy sources (e.g., laser diode array) and/or fluxes.Alternatively or additionally the target surface, material bed, 3Dobject (or part thereof), or any combination thereof may be heated by aheating mechanism. The heating mechanism may comprise dispersed energybeams. In some cases, the at least one energy source is a single (e.g.,first) energy source.

An energy source can be a source configured to deliver energy to an area(e.g., a confined area). An energy source can deliver energy to theconfined area through radiative heat transfer. The energy source canproject energy (e.g., heat energy, and/or energy beam). The energy(e.g., beam) can interact with at least a portion of the material bed.The energy can heat the material bed portion before, during and/or afterthe material is being transformed. The energy can heat at least afraction of a 3D object at any point during formation of the 3D object.Alternatively or additionally, the material bed may be heated by aheating mechanism projecting energy (e.g., radiative heat and/or energybeam). The energy may include an energy beam and/or dispersed energy(e.g., radiator or lamp). The radiative heat may be projected by adispersive energy source (e.g., a heating mechanism) comprising a lamp,a strip heater (e.g., mica strip heater, or any combination thereof), aheating rod (e.g., quartz rod), or a radiator (e.g., a panel radiator).The heating mechanism may comprise an inductance heater. The heatingmechanism may comprise a resistor (e.g., variable resistor). Theresistor may comprise a varistor or rheostat. A multiplicity ofresistors may be configured in series, parallel, or any combinationthereof. In some cases, the system can have a single (e.g., first)energy source. An energy source can be a source configured to deliverenergy to an area (e.g., a confined area). An energy source can deliverenergy to the confined area through radiative heat transfer (e.g., asdescribed herein).

In some examples, the energy beam includes a radiation comprising anelectromagnetic, or charged particle beam. The energy beam may includeradiation comprising electromagnetic, electron, positron, proton,plasma, or ionic radiation. The electromagnetic beam may comprisemicrowave, infrared, ultraviolet, or visible radiation. The energy beammay include an electromagnetic energy beam, electron beam, particlebeam, or ion beam. An ion beam may include a cation or an anion. Aparticle beam may include radicals. The electromagnetic beam maycomprise a laser beam. The energy beam may comprise plasma. The energysource may include a laser source. The energy source may include anelectron gun. The energy source may include an energy source capable ofdelivering energy to a point or to an area. In some embodiments, theenergy source is a laser source. The laser source may comprise a CO₂,Nd:YAG, Neodymium (e.g., neodymium-glass), an Ytterbium, or an excimerlaser. The laser may be a fiber laser. The energy source may include anenergy source capable of delivering energy to a point or to an area. Theenergy source (e.g., first scanning energy source) can provide an energybeam having an energy density of at least about 50 joules/cm² (J/cm²),100 J/cm², 200 J/cm², 300 J/cm², 400 J/cm², 500 J/cm², 600 J/cm², 700J/cm², 800 J/cm², 1000 J/cm², 1500 J/cm², 2000 J/cm², 2500 J/cm², 3000J/cm², 3500 J/cm², 4000 J/cm², 4500 J/cm², or 5000 J/cm². The energysource (e.g., first scanning energy source) can provide an energy beamhaving an energy density of at most about 50 J/cm², 100 J/cm², 200J/cm², 300 J/cm², 400 J/cm², 500 J/cm², 600 J/cm², 700 J/cm², 800 J/cm²,1000 J/cm², 500 J/cm², 1000 J/cm², 1500 J/cm², 2000 J/cm², 2500 J/cm²,3000 J/cm², 3500 J/cm², 4000 J/cm², 4500 J/cm², or 5000 J/cm². Theenergy source (e.g., first scanning energy source) can provide an energybeam having an energy density of a value between the afore-mentionedvalues (e.g., from about 50 J/cm² to about 5000 J/cm², from about 200J/cm² to about 1500 J/cm², from about 1500 J/cm² to about 2500 J/cm²,from about 100 J/cm² to about 3000 J/cm², or from about 2500 J/cm² toabout 5000 J/cm²). In an example a laser (e.g., first scanning energysource) can provide light energy at a peak wavelength of at least about100 nanometer (nm), 400 nm, 500 nm, 750 nm, 1000 nm, 1010 nm, 1020 nm,1030 nm, 1040 nm, 1050 nm, 1060 nm, 1070 nm, 1080 nm, 1090 nm, 1100 nm,1200 nm, 1500 nm, 1600 nm, 1700 nm, 1800 nm, 1900 nm, or 2000 nm. In anexample a laser can provide light energy at a peak wavelength of at mostabout 2000 nm, 1900 nm, 1800 nm, 1700 nm, 1600 nm, 1500 nm, 1200 nm,1100 nm, 1090 nm, 1080 nm, 1070 nm, 1060 nm, 1050 nm, 1040 nm, 1030 nm,1020 nm, 1010 nm, 1000 nm, 750 nm, 500 nm, 400 nm, or 100 nm. The lasercan provide light energy at a peak wavelength between any of theafore-mentioned peak wavelength values (e.g., from about 100 nm to about2000 nm, from about 500 nm to about 1500 nm, or from about 1000 nm toabout 1100 nm). The energy source (e.g., laser) may have a power of atleast about 0.5 Watt (W), 1 W, 2 W, 3 W, 4 W, 5 W, 10 W, 20 W, 30 W, 40W, 50 W, 60 W, 70 W, 80 W, 90 W, 100 W, 120 W, 150 W, 200 W, 250 W, 300W, 350 W, 400 W, 500 W, 750 W, 800 W, 900 W, 1000 W, 1500 W, 2000 W,3000 W, or 4000 W. The energy source may have a power of at most about0.5 W, 1 W, 2 W, 3 W, 4 W, 5 W, 10 W, 20 W, 30 W, 40 W, 50 W, 60 W, 70W, 80 W, 90 W, 100 W, 120 W, 150 W, 200 W, 250 W, 300 W, 350 W, 400 W,500 W, 750 W, 800 W, 900 W, 1000 W, 1500, 2000 W, 3000 W, or 4000 W. Theenergy source may have a power between any of the afore-mentioned laserpower values (e.g., from about 0.5 W to about 100 W, from about 1 W toabout 10 W, from about 100 W to about 1000 W, or from about 1000 W toabout 4000 W). The first energy source (e.g., producing the firstscanning energy beam) may have at least one of the characteristics ofthe second energy source (e.g., producing the second scanning energybeam). The tiling energy flux may have at least one of thecharacteristics disclosed herein for the energy beam. The tiling energyflux may be generated from the same energy source or from differentenergy sources as compared with the scanning energy beam. The tilingenergy flux may be of a lesser power density as compared to the scanningenergy beam. Lesser power may be by about 0.25, 0.5, 0.75, or 1 (one)order of magnitude. The scanning energy beam may operate independentlyor synchronously with the tiling energy flux (e.g., during the 3Dprinting). In some examples, the scanning energy beam and the tilingenergy flux are generated by the same energy source that operates in twomodules (e.g., different modules) respectively.

An energy beam from the energy source(s) can be incident on, or bedirected perpendicular to, the target surface. An energy beam from theenergy source(s) can be directed at an acute angle within a value offrom parallel to perpendicular relative to the target surface. Theenergy beam can be directed to a pre-transformed and/or a transformedmaterial for a specified time-period. That pre-transformed and/or atransformed material can absorb the energy from the energy beam and, andas a result, a localized region of the material bed can increase intemperature. The energy beam can be moveable (e.g., using a scanner)such that it can translate relative to the target surface. At times, theenergy source of the irradiated energy is movable such that it cantranslate relative to the target surface. At times, the energy source ofthe irradiated energy is stationary. At least two (e.g., all) of theenergy sources can be movable with the same scanner. A least two (e.g.,all) of the energy beams can be movable with the same scanner. At leasttwo of the energy source(s) and/or beam(s) can be translatedindependently of each other. In some cases, at least two of the energysource(s) and/or beam(s) can be translated at different rates (e.g.,velocities). In some cases, at least two of the energy source(s) and/orbeam(s) can be comprise at least one different characteristic. Thecharacteristics of the irradiated energy may comprise wavelength, power,amplitude, trajectory, footprint, intensity, energy, fluence, AndrewNumber, hatch spacing, scan speed, or charge. The charge can beelectrical and/or magnetic charge. Andrew number is proportional to thepower of the irradiating energy over the multiplication product of itsvelocity (e.g., scan speed) by the its hatch spacing. The Andrew numberis at times referred to as the area filling power of the irradiatingenergy.

The energy source can be an array, or a matrix, of energy sources (e.g.,laser diodes). Each of the energy sources in the array, or matrix, canbe independently controlled (e.g., by a control mechanism) such that theenergy beams can be turned off and on independently. At least a part ofthe energy sources in the array or matrix can be collectively controlledsuch that the at least two (e.g., all) of the energy sources can beturned off and on simultaneously. In some embodiments, the energy perunit area (or intensity) of at least two energy sources in the matrix orarray are modulated independently (e.g., by a control mechanism orsystem). At times, the energy per unit area or intensity of at least two(e.g., all) of the energy sources in the matrix or array is modulatedsimultaneously (e.g., by a control mechanism). The energy source canscan along target surface by mechanical movement of the energysource(s), one or more adjustable reflective mirrors, and/or one or morepolygon light scanners. The energy source(s) can project energy using aDLP modulator, a one-dimensional scanner, a two-dimensional scanner, orany combination thereof. The target and/or source surface can translatevertically, horizontally, or in an angle (e.g., planar or compound).

The energy source can comprise a modulator. The irradiated energy by theenergy source can be modulated. The modulator can include amplitudemodulator, phase modulator, or polarization modulator. The modulationmay alter the intensity of the energy beam. The modulation may alter thecurrent supplied to the energy source (e.g., direct modulation). Themodulation may affect the irradiated energy (e.g., external modulationsuch as external light modulator). The modulation may include directmodulation (e.g., by a modulator). The modulation may include anexternal modulator. The modulator can include an aucusto-optic modulatoror an electro-optic modulator. The modulator can comprise an absorptivemodulator or a refractive modulator. The modulation may alter theabsorption coefficient the material that is used to modulate the energybeam. The modulator may alter the refractive index of the material thatis used to modulate the energy beam.

In some examples, the irradiated energy is moveable relative to thetarget surface such that it can translate relative to the targetsurface. The scanner may comprise a galvanometer scanner, a polygon, amechanical stage (e.g., X-Y stage), a piezoelectric device, gimble, orany combination of thereof. The galvanometer may comprise a mirror. Thescanner may comprise a modulator. The scanner may comprise a polygonalmirror. The scanner can be the same scanner for two or more energysources and/or beams. At least two (e.g., each) energy source and/orbeam may have a separate scanner. The energy sources can be translatedindependently of each other. In some cases, at least two irradiatedenergies (e.g., the scanning energy beam and the tiling energy flux) canbe translated at different rates, along different trajectories, and/oralong different paths (e.g., during formation of a layer of hardenedmaterial). For example, the movement of the scanning energy beam may befaster (e.g., greater rate) as compared to the movement of the tilingenergy flux. In some embodiments, the systems and/or apparatusesdisclosed herein comprise one or more shutters (e.g., safety shutters).The galvanometer scanner may comprise a two-axis galvanometer scanner.The scanner may comprise a modulator (e.g., as described herein). Theenergy source(s) can project energy and translate it using a DLPmodulator, a one-dimensional scanner, a two-dimensional scanner, or anycombination thereof. The energy source(s) can be stationary ortranslatable. The irradiated energy can translate vertically,horizontally, or in an angle (e.g., planar or compound angle). Thescanner can be included in an optical system that is configured todirect energy from the energy source to a predetermined position on thetarget surface (e.g., exposed surface of the material bed). Thecontroller can be programmed to control a trajectory of the irradiatedenergy with the aid of the optical system. The controller can regulate asupply of energy from the energy source to the material (e.g., at thetarget surface) to form a transformed material.

In some embodiments, the layer dispensing mechanism dispenses thematerial, level, distribute, spread, and/or remove the material in amaterial bed. The layer dispensing mechanism may comprise at least one,two or three of (i) a material dispensing mechanism, (ii) materialremoval mechanism, and (iii) material leveling mechanism. The layerdispensing mechanism may be controlled by the controller. At least apart (e.g., portion and/or component) of the layer dispensing mechanismmay be temperature regulated (e.g., heated, temperature maintained, orcooled). At least one component within the layer dispensing mechanismmay be heated or cooled. At least one component within the layerdispensing mechanism that contacts the material (e.g., powder and/ortransformed material) may be heated or cooled. The movement of the layerdispensing mechanism may be programmable. The movement of the layerdispensing mechanism may be predetermined. The movement of the layerdispensing mechanism may be according to an algorithm (e.g., consideringthe model of the 3D object).

In some embodiments, the layer dispensing mechanism or any of itscomponents are exchangeable, removable, non-removable, ornon-exchangeable. The layer dispensing mechanism (e.g., any of itscomponents) may comprise exchangeable parts. The layer dispensingmechanism may distribute material across the target surface. The layerdispensing mechanism or any of its components (e.g., flatteningmechanism) can provide a pre-transformed material (e.g., powder)uniformity across the target surface (e.g., exposed surface of thematerial bed) such that portions of the target surface (e.g., thatcomprise the dispensed material) that are separated from one another byat least about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, or 10 mm, have a heightdeviation of at most about 10 mm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3mm, 2 mm, 1 mm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, 90 μm, 80, 70μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, or 10 μm; or of any value betweenthe afore-mentioned height deviation values (e.g., from about 10 μm toabout 10 mm, from about 10 μm to about 1 mm, from about 50 μm to about100 μm, from about 40 μm to about 200 μm, or from about 10 μm to about200 μm). The layer dispensing mechanism may achieve a deviation from aplanar uniformity of the target surface in at least one plane (e.g.,horizontal plane) of at most about 20%, 10%, 5%, 2%, 1% or 0.5%, ascompared to the average plane (e.g., horizontal plane) created at thetarget surface (e.g., top of a powder bed). The layer dispensed by thelayer dispensing mechanism may be substantially planar (e.g., flat). Theexposed surface that was leveled by the planarizing mechanism may besubstantially planar (e.g., flat). The exposed surface that was leveledby the leveling and/or material removal mechanism may be substantiallyplanar (e.g., flat).

In some examples, at least two components of the layer dispensingmechanism (e.g., material dispensing mechanism, leveling member, and/ormaterial removal member) are individually or jointly controlled. Jointlycontrolled may include simultaneously controlled. Individuallycontrolled may be non-simultaneously controlled. Individually controlledmay be separately controlled. At least one component of the layerdispensing mechanism follows another component relative to the directionof travel. When the layer dispensing mechanism reaches the end of thematerial bed, or precedes the end of the powder bed, the direction ofmovement may switch. Sometimes, the switch may involve concertedalteration of the relative positions of the components of the layerdispensing mechanism. Sometimes, the switch may not involve concertedalteration of the relative positions of the components of the layerdispensing mechanism. The layer dispensing mechanism and it componentsmay be any of the ones disclosed in U.S. 62/317,070 or PCT/US15/36802,both of which are entirely incorporated herein by reference.

In some examples, the systems and/or apparatuses disclosed hereincomprise a material removal mechanism. The material removal mechanismmay be any material removal mechanism disclosed in PCT/US15/36802, whichis fully incorporated herein by reference. The material removalmechanism may be coupled to the material dispensing mechanism and/or thematerial leveling mechanism. The material removal mechanism can bedisposed adjacent to (e.g., above, below, or to the side of) thematerial bed. The material removal mechanism may translatablehorizontally, vertically, or at an angle. The powder removal mechanismmay be movable. The removal mechanism may be movable manually and/orautomatically (e.g., controlled by a controller). The movement of thematerial removal mechanism may be programmable. The movement of thematerial removal mechanism may be predetermined. The movement of thepowder removal mechanism may be according to an algorithm.

In some examples, the material removal mechanism comprises a materialentrance opening port and a material exit opening port. The materialentrance port and material exit port may be the same opening. Thematerial entrance port and material exit port may be different openings.The material entrance and material exit ports may be spatiallyseparated. The spatial separation may be on the external surface of thematerial removal mechanism. The spatial separation may be on the surfacearea of the material removal mechanism. The material entrance andmaterial exit ports may be connected. The material entrance and materialexit ports may be connected within the material removal mechanism. Theconnection may be an internal cavity within the material removalmechanism.

In some embodiments, the material removal mechanism comprises a forcethat causes the material to travel from the material bed (e.g., exposedsurface thereof) towards the interior of the material removal mechanism(e.g., the reservoir). That travel may be in an anti-gravitationalmanner and/or upwards direction. The material removal mechanism maycomprise negative pressure (e.g., vacuum), electrostatic force, electricforce, magnetic force, or physical force. In some examples, the materialremoval mechanism does not contact the target surface while removingmaterial from it. For example, the material removal mechanism isseparated from the target surface by a gas gap. The material dispensingmechanism may comprise negative pressure (e.g., vacuum) that causes thematerial to leave the target surface and travel into the entranceopening of the material removal mechanism. The material dispensingmechanism may comprise positive pressure (e.g., a gas flow) that causesthe material to leave the target surface and travel into the entranceopening of the material removal mechanism. The gas may comprise any gasdisclosed herein. The gas may aid in fluidizing the pre-transformedmaterial (e.g., powder) that remains in the material bed. The removedmaterial may be recycled and re-applied into the source surface by thematerial dispensing mechanism. The pre-transformed material may becontinuously recycled through the operation of the material removalsystem. The pre-transformed material may be recycled after each layer ofmaterial has been removed (e.g., from the source surface). Thepre-transformed material may be recycled after several layers ofmaterial have been removed. The pre-transformed material may be recycledafter each 3D object has been printed.

Any of the material removal mechanism described herein can comprise areservoir of pre-transformed material and/or a mechanism configured todeliver the pre-transformed material from the reservoir to the materialdispensing mechanism. The pre-transformed material in the reservoir canbe treated. The treatment may include heating, cooling, maintaining apredetermined temperature, sieving, filtering, charging, or fluidizing(e.g., with a gas). The reservoir can be emptied after eachpre-transformed material layer has been deposited and/or leveled, at theend of the build cycle, and/or at a whim. The reservoir can becontinuously emptied during the operation of the material removalmechanism. At times, the material removal mechanism does not have areservoir. At times, the material removal mechanism is (e.g., fluidly)connected to a reservoir. At times, the material removal mechanismconstitutes a material removal (e.g., a suction) channel that leads toan external reservoir and/or to the material dispensing mechanism. Thematerial removal and/or dispensing mechanism may comprise an internalreservoir and/or an opening port. The reservoir of the materialdispensing mechanism and/or the material removal mechanism can be of anyshape. For example, the reservoir can be a tube (e.g., flexible orrigid). The reservoir can be a funnel. The reservoir can have arectangular cross section or a conical cross section. The reservoir canhave an amorphous shape.

The material removal mechanism may include one or more suction nozzles.The suction nozzle may comprise any of the nozzles described herein. Thenozzles may comprise of a single opening or a multiplicity of openingsas described herein. The openings may be vertically leveled or notleveled. The openings may be vertically aligned, or misaligned (e.g.,FIGS. 13, 1317, 1318, and 1319). In some examples, at least two of themultiplicity of openings may be misaligned. The multiplicity suctionnozzles may be aligned at the same height relative to the surface (e.g.,source surface), or at different heights (e.g., vertical height). Thedifferent height nozzles may form a pattern, or may be randomly situatedin the suction device. The nozzles may be of one type, or of differenttypes. The material removal mechanism (e.g., suction device) maycomprise a curved surface, for example adjacent to a side of a nozzle(e.g., FIG. 33, 3320). Pre-transformed material that enters through thenozzle (e.g., along 3301) may be collected at the curved surface. Thenozzle may comprise a cone. The cone may be a converging cone or adiverging cone.

In an example, the material removal mechanism travels laterally beforethe leveling mechanism (e.g., a roller) relative to the direction ofmovement. In an example, the material removal mechanism travelslaterally after the leveling mechanism, relative to the direction ofmovement. The material removal mechanism may be integrated (e.g.,electronically and/or mechanically) with the leveling mechanism. Thematerial removal mechanism may be (e.g., reversibly) connected to theleveling mechanism (e.g., FIG. 34D, 3443 and 3447). The material removalmechanism may be disconnected from the leveling mechanism.

In some embodiments, the material removal mechanism and the materialdispensing mechanism are integrated into one mechanism (e.g., FIG. 28C).For example, the exit opening ports of the material dispensing mechanismand the material entrance ports of the material removal mechanism may beintegrated into a single mechanical components. For example, the twoport types may be arranged in a single file. For example, the two porttypes may be interchangeably arranged. The material removal mechanismmay comprise an array of material entry ports (e.g., suction devices ornozzles). The ports (e.g., material entry and/or exit ports) within thearray may be spaced apart evenly or unevenly. The ports within the arraymay be spaced apart at most about 0.1 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 3mm, 4 mm, or 5 mm. The ports within the array may be spaced apart atleast about 0.1 mm, 0.3 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, or 5mm. The ports within the array may be spaced apart between any of theafore-mentioned spaces (e.g., from about 0.1 mm to about 5 mm, fromabout 0.1 mm to about 2 mm, from about 1.5 mm to about 5 mm).

In some embodiments, one or more sensors (at least one sensor) detectthe topology of the exposed surface of the material bed and/or theexposed surface of the 3D object or any part thereof. The sensor candetect the amount of material deposited on the target surface. Thesensor can be a proximity sensor. For example, the sensor can detect theamount of pre-transformed material deposited on the exposes surface of amaterial bed. The sensor can detect the physical state of materialdeposited on the target surface (e.g., liquid or solid (e.g., powder orbulk)). The sensor can detect the crystallinity of pre-transformedmaterial deposited on the target surface. The sensor can detect theamount of pre-transformed material deposited by the material dispensingmechanism. The sensor can detect the amount of relocated by a levelingmechanism. The sensor can detect the temperature of the pre-transformedmaterial. For example, the sensor may detect the temperature of the in amaterial dispensing mechanism, and/or in the material bed. The sensormay detect the temperature of the material during and/or after itstransformation (e.g., in real-time). The sensor may detect thetemperature and/or pressure of the atmosphere within an enclosure (e.g.,chamber). The sensor may detect the temperature of the material (e.g.,powder) bed at one or more locations. The detection by the sensor can bebefore, after, and/or during the 3D printing (e.g., in real-time).

In some embodiments, the at least one sensor is operatively coupled to acontrol system (e.g., computer control system). The sensor may compriselight sensor, acoustic sensor, vibration sensor, chemical sensor,electrical sensor, magnetic sensor, fluidity sensor, movement sensor,speed sensor, position sensor, pressure sensor, force sensor, densitysensor, distance sensor, or proximity sensor. The sensor may includetemperature sensor, weight sensor, material (e.g., powder) level sensor,metrology sensor, gas sensor, or humidity sensor. The metrology sensormay comprise a measurement sensor (e.g., height, length, width, angle,and/or volume). For example, the metrology sensor can be a heightsensor. The metrology sensor may comprise a magnetic, acceleration,orientation, or optical sensor. The sensor may transmit and/or receivesound (e.g., echo), magnetic, electronic, or electromagnetic signal. Theelectromagnetic signal may comprise a visible, infrared, ultraviolet,ultrasound, radio wave, or microwave signal. The metrology sensor maymeasure (e.g., a metrology property of) the tile. The metrology sensormay measure the gap. The metrology sensor may measure at least a portionof the layer of material. The layer of material may be a pre-transformedmaterial (e.g., powder), transformed material, or hardened material. Themetrology sensor may measure at least a portion of the 3D object. Thegas sensor may sense any of the gas delineated herein. The distancesensor can be a type of metrology sensor. The distance sensor maycomprise an optical sensor, or capacitance sensor. The temperaturesensor can comprise Bolometer, Bimetallic strip, calorimeter, Exhaustgas temperature gauge, Flame detection, Gardon gauge, Golay cell, Heatflux sensor, Infrared thermometer, Microbolometer, Microwave radiometer,Net radiometer, Quartz thermometer, Resistance temperature detector,Resistance thermometer, Silicon band gap temperature sensor, Specialsensor microwave/imager, Temperature gauge, Thermistor, Thermocouple,Thermometer (e.g., resistance thermometer), or Pyrometer. Thetemperature sensor may comprise an optical sensor. The temperaturesensor may comprise image processing. The temperature sensor maycomprise a camera (e.g., IR camera, CCD camera). The pressure sensor maycomprise Barograph, Barometer, Boost gauge, Bourdon gauge, Hot filamentionization gauge, Ionization gauge, McLeod gauge, Oscillating U-tube,Permanent Downhole Gauge, Piezometer, Pirani gauge, Pressure sensor,Pressure gauge, Tactile sensor, or Time pressure gauge. The positionsensor may comprise Auxanometer, Capacitive displacement sensor,Capacitive sensing, Free fall sensor, Gravimeter, Gyroscopic sensor,Impact sensor, Inclinometer, Integrated circuit piezoelectric sensor,Laser rangefinder, Laser surface velocimeter, LIDAR, Linear encoder,Linear variable differential transformer (LVDT), Liquid capacitiveinclinometers, Odometer, Photoelectric sensor, Piezoelectricaccelerometer, Rate sensor, Rotary encoder, Rotary variable differentialtransformer, Selsyn, Shock detector, Shock data logger, Tilt sensor,Tachometer, Ultrasonic thickness gauge, Variable reluctance sensor, orVelocity receiver. The optical sensor may comprise a Charge-coupleddevice, Colorimeter, Contact image sensor, Electro-optical sensor,Infra-red sensor, Kinetic inductance detector, light emitting diode(e.g., light sensor), Light-addressable potentiometric sensor, Nicholsradiometer, Fiber optic sensors, Optical position sensor, Photodetector, Photodiode, Photomultiplier tubes, Phototransistor,Photoelectric sensor, Photoionization detector, Photomultiplier, Photoresistor, Photo switch, Phototube, Scintillometer, Shack-Hartmann,Single-photon avalanche diode, Superconducting nanowire single-photondetector, Transition edge sensor, Visible light photon counter, or Wavefront sensor. The weight of the material bed can be monitored by one ormore weight sensors in, or adjacent to, the material. For example, aweight sensor in the material bed can be at the bottom of the materialbed. The weight sensor can be between the bottom of the enclosure (e.g.,FIG. 1, 111) and the substrate (e.g., FIG. 1, 109) on which the base(e.g., FIG. 1, 102) or the material bed (e.g., FIG. 1, 104) may bedisposed. The weight sensor can be between the bottom of the enclosureand the base on which the material bed may be disposed. The weightsensor can be between the bottom of the enclosure and the material bed.A weight sensor can comprise a pressure sensor. The weight sensor maycomprise a spring scale, a hydraulic scale, a pneumatic scale, or abalance. At least a portion of the pressure sensor can be exposed on abottom surface of the material bed. In some cases, the weight sensor cancomprise a button load cell. The button load cell can sense pressurefrom pre-transformed material adjacent to the load cell. In anotherexample, one or more sensors (e.g., optical sensors or optical levelsensors) can be provided adjacent to the material bed such as above,below, or to the side of the material bed. In some examples, the one ormore sensors can sense the pre-transformed material level (e.g., heightor volume). The pre-transformed material level sensor can be incommunication with a material dispensing mechanism (e.g., powderdispenser). Alternatively, or additionally a sensor can be configured tomonitor the weight of the material bed by monitoring a weight of astructure that contains the material bed. One or more position sensors(e.g., height sensors) can measure the height of the material bedrelative to the substrate. The position sensors can be optical sensors.The position sensors can determine a distance between one or more energybeams (e.g., a laser or an electron beam.) and a surface of the material(e.g., powder). The one or more sensors may be connected to a controlsystem (e.g., to a processor, to a computer).

The systems and/or apparatuses disclosed herein may comprise one or moreactuators. The actuator may comprise a motor. The motors may compriseservomotors. The servomotors may comprise actuated linear lead screwdrive motors. The motors may comprise belt drive motors. The motors maycomprise rotary encoders. The apparatuses and/or systems may compriseswitches. The switches may comprise homing or limit switches. The motorsmay comprise actuators. The actuators may comprise linear actuators. Themotors may comprise belt driven actuators. The motors may comprise leadscrew driven actuators. The systems and/or apparatuses disclosed hereinmay comprise one or more pistons.

In some examples, the pressure system includes one or more pumps. Theone or more pumps may comprise a positive displacement pump. Thepositive displacement pump may comprise rotary-type positivedisplacement pump, reciprocating-type positive displacement pump, orlinear-type positive displacement pump. The positive displacement pumpmay comprise rotary lobe pump, progressive cavity pump, rotary gearpump, piston pump, diaphragm pump, screw pump, gear pump, hydraulicpump, rotary vane pump, regenerative (peripheral) pump, peristalticpump, rope pump, or flexible impeller. Rotary positive displacement pumpmay comprise gear pump, screw pump, or rotary vane pump. Thereciprocating pump comprises plunger pump, diaphragm pump, piston pumpsdisplacement pumps, or radial piston pump. The pump may comprise avalveless pump, steam pump, gravity pump, eductor-jet pump, mixed-flowpump, bellow pump, axial-flow pumps, radial-flow pump, velocity pump,hydraulic ram pump, impulse pump, rope pump, compressed-air-powereddouble-diaphragm pump, triplex-style plunger pump, plunger pump,peristaltic pump, roots-type pumps, progressing cavity pump, screw pump,or gear pump. The pump may be a vacuum pump. The one or more vacuumpumps may comprise Rotary vane pump, diaphragm pump, liquid ring pump,piston pump, scroll pump, screw pump, Wankel pump, external vane pump,roots blower, multistage Roots pump, Toepler pump, or Lobe pump. The oneor more vacuum pumps may comprise momentum transfer pump, regenerativepump, entrapment pump, Venturi vacuum pump, or team ejector. Thepressure system can include valves; such as throttle valves.

The systems, apparatuses, and/or methods described herein can comprise amaterial recycling mechanism. The recycling mechanism can collect unusedpre-transformed material and return the unused pre-transformed materialto a reservoir. The reservoir can be of a material dispensing mechanism(e.g., the material dispensing reservoir), or to the bulk reservoir thatfeeds into the material dispensing mechanism. Unused pre-transformedmaterial may be material that was not used to form at least a portion ofthe 3D object. At least a fraction of the pre-transformed materialremoved from the material bed by the leveling mechanism and/or materialremoval mechanism can be recovered by the recycling system. At least afraction of the material within the material bed that did not transformto subsequently form the 3D object can be recovered by the recyclingsystem. A vacuum nozzle (e.g., which can be located at an edge of thematerial bed) can collect unused pre-transformed material. Unusedpre-transformed material can be removed from the material bed withoutvacuum. Unused pre-transformed (e.g., powder) material can be removedfrom the material bed manually. Unused pre-transformed material can beremoved from the material bed by positive pressure (e.g., by blowingaway the unused material). Unused pre-transformed material can beremoved from the material bed by actively pushing it from the materialbed (e.g., mechanically or using a positive pressurized gas). Unusedpre-transformed material can be removed from the material bed by thematerial removal mechanism. Unused pre-transformed material can beremoved from the material bed by utilizing the force source. A gas flowcan direct unused pre-transformed material to the vacuum nozzle. Amaterial collecting mechanism (e.g., a shovel) can direct unusedmaterial to exit the material bed (and optionally enter the recyclingmechanism). The recycling mechanism can comprise one or more filters tocontrol a size range of the particles returned to the reservoir. In somecases, a Venturi scavenging nozzle can collect unused material. Thenozzle can have a high aspect ratio (e.g., at least about 2:1, 5:1,10:1, 20:1, 30:1, 40:1, or 100:1) such that the nozzle does not becomeclogged with material particle(s). In some embodiments, the material maybe collected by a drainage mechanism through one or more drainage portsthat drain material from the material bed into one or more drainagereservoirs. The material in the one or more drainage reservoirs may bere used (e.g., after filtration and/or further treatment).

In some cases, unused material can surround the 3D object in thematerial bed. The unused material can be substantially removed from the3D object. In some embodiments, the unused material is removed from the3D object in the environment (e.g., atmosphere and/or enclosure) inwhich the 3D object is printed. In some embodiments, the unused materialis removed from the 3D object in a different environment (e.g.,atmosphere and/or enclosure) from the one in which the 3D object isprinted. The unused material is referred herein as the “remainder.”Substantial removal may refer to material covering at most about 20%,15%, 10%, 8%, 6%, 4%, 2%, 1%, 0.5%, or 0.1% of the surface of the 3Dobject after removal. Substantial removal may refer to removal of allthe material that was disposed in the material bed and remained asmaterial at the end of the 3D printing process (i.e., the remainder),except for at most about 10%, 3%, 1%, 0.3%, or 0.1% of the weight of theremainder. Substantial removal may refer to removal of all the remainderexcept for at most abbot 50%, 10%, 3%, 1%, 0.3%, or 0.1% of the weightof the printed 3D object. The unused material can be removed to permitretrieval of the 3D object without digging through the material bed. Forexample, the unused material can be suctioned out of the material bed byone or more vacuum ports (e.g., nozzles) built adjacent to the materialbed, by brushing off the remainder of unused material, by lifting the 3Dobject from the unused material, by allowing the unused material to flowaway from the 3D object (e.g., by opening an exit opening port on theside(s) or on the bottom of the material bed from which the unusedmaterial can exit). After the unused material is evacuated, the 3Dobject can be removed and the unused material can be re-circulated to amaterial reservoir for use in future builds. Unused material can beremoved from the 3D object by system and apparatuses to clean a 3Dobject (e.g., FIG. 16), such as the one disclosed in U.S. 62/317,070,and in PCT/US15/36802, each of which is entirely incorporated herein byreference.

In some embodiments, the final form of the 3D object is retrieved soonafter cooling of a final material layer. Soon after cooling may be atmost about 1 day, 12 hours (h), 6 h, 5 h, 4 h, 3 h, 2 h, 1 h, 30minutes, 15 minutes, 5 minutes, 240 s, 220 s, 200 s, 180 s, 160 s, 140s, 120 s, 100 s, 80 s, 60 s, 40 s, 20 s, 10 s, 9 s, 8 s, 7 s, 6 s, 5 s,4 s, 3 s, 2 s, or 1 s. Soon after cooling may be between any of theafore-mentioned time values (e.g., from about is to about 1 day, fromabout is to about 1 hour, from about 30 minutes to about 1 day, or fromabout 20 s to about 240 s). In some cases, the cooling can occur bymethod comprising active cooling by convection using a cooled gas or gasmixture comprising argon, nitrogen, helium, neon, krypton, xenon,hydrogen, carbon monoxide, carbon dioxide, or oxygen. Cooling may becooling to a temperature that allows a person to handle the 3D object.Cooling may be cooling to a handling temperature. The 3D object can beretrieved during a time-period between any of the afore-mentionedtime-periods (e.g., from about 12 h to about 1 s, from about 12 h toabout 30 min, from about 1 h to about 1 s, or from about 30 min to about40 s).

In some embodiments, the generated 3D object requires very little or nofurther processing after its retrieval. In some examples, the diminishedfurther processing or lack thereof, will afford a 3D printing processthat requires smaller amount of energy and/or less waste as compared tocommercially available 3D printing processes. The smaller amount can besmaller by at least about 1.1, 1.3, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, or 10.The smaller amount may be smaller by any value between theafore-mentioned values (e.g., from about 1.1 to about 10, or from about1.5 to about 5). Further processing may comprise trimming, as disclosedherein. Further processing may comprise polishing (e.g., sanding). Forexample, in some cases the generated 3D object can be retrieved andfinalized without removal of transformed material and/or auxiliaryfeatures. The 3D object can be retrieved when the three-dimensionalpart, composed of hardened (e.g., solidified) material, is at a handlingtemperature that is suitable to permit the removal of the 3D object fromthe material bed without substantial deformation. The handlingtemperature can be a temperature that is suitable for packaging of the3D object. The handling temperature a can be at most about 120° C., 100°C., 80° C., 60° C., 40° C., 30° C., 25° C., or 20° C. The handlingtemperature can be of any value between the afore-mentioned temperaturevalues (e.g., from about 120° C. to about 20° C.).

The methods and systems provided herein can result in fast and efficientformation of 3D objects. In some cases, the 3D object can be transportedat a rate of at least about 0.1 centimeters squared per second(cm²/sec), 0.5 cm²/sec, 1.0 cm²/sec, 1.5 cm²/sec, 2.0 cm²/sec, 2.5cm²/sec, 5 cm²/sec, 10 cm²/sec, 15 cm²/sec, 20 cm²/sec, 30 cm²/sec, 50cm²/sec, 70 cm²/sec, 80 cm²/sec, 90 cm²/sec, 100 cm²/sec, or 120cm²/sec. In some cases, the 3D object is transported at a rate that isbetween the above-mentioned rates (e.g., from about 0.1 cm²/sec to about120 cm²/sec, from about 1.5 cm²/sec to about 80 cm²/sec, or from about1.0 cm²/sec to about 100 cm²/sec). In some examples, the 3D part has theherein stated accuracy value immediately after its formation, withoutadditional processing and/or manipulation.

In some embodiments, one or more 3D object (e.g., a stock of 3D objects)are supplied to a customer. A customer can be an individual, acorporation, organization, government, non-profit organization, company,hospital, medical practitioner, engineer, retailer, any other entity, orindividual. The customer may be one that is interested in receiving the3D object and/or that ordered the 3D object. A customer can submit arequest for formation of a 3D object. The customer can provide an itemof value in exchange for the 3D object. The customer can provide adesign or a model for the 3D object. The customer can provide the designin the form of a stereo lithography (STL) file. The customer can providea design where the design can be a definition of the shape anddimensions of the 3D object in any other numerical or physical form. Insome cases, the customer can provide a 3D model, sketch, or image as adesign of an object to be generated. The design can be transformed in toinstructions usable by the printing system to additively generate the 3Dobject. The customer can provide a request to form the 3D object from aspecific material or group of materials (e.g., a material as describedherein). In some cases, the design may not contain auxiliary features ormarks of any past presence of auxiliary support features.

In an embodiment, in response to the customer request the 3D object isformed with the printing method, system and/or apparatus describedherein, using one or more materials as specified by the customer. The 3Dobject can subsequently be delivered to the customer. The 3D object canbe formed without generation or removal of auxiliary features (e.g.,that is indicative of a presence or removal of the auxiliary supportfeature). Auxiliary features can be support features that prevent a 3Dobject from shifting, deforming or moving during the 3D printing.

In some instances, the intended dimensions of the 3D object derive froma model design of the 3D object. The 3D object (e.g., solidifiedmaterial) that is generated for the customer can have an averagedeviation value from the intended dimensions of at most about 0.5microns (μm), 1 μm, 3 μm, 10 μm, 30 μm, 100 μm, 300 μm, or less. Thedeviation can be any value between the afore-mentioned values (e.g.,from about 0.5 μm to about 300 μm, from about 10 μm to about 50 μm, fromabout 15 μm to about 85 μm, from about 5 μm to about 45 μm, or fromabout 15 μm to about 35 μm). The 3D object can have a deviation from theintended dimensions in a specific direction, according to the formulaDv+L/K_(Dv), wherein Dv is a deviation value, L is the length of the 3Dobject in a specific direction, and K_(Dv) is a constant. Dv can have avalue of at most about 300 μm, 200 μm, 100 μm, 50 μm, 40 μm, 30 μm, 20μm, 10 μm, 5 μm, 1 μm, or 0.5 μm. Dv can have a value of at least about0.5 μm, 1 μm, 3 μm, 5 μm, 10 μm, 20 μm, 30 μm, 50 μm, 70 μm, 100 μm, or300 μm. Dv can have any value between the afore-mentioned values (e.g.,from about 0.5 μm to about 300 μm, from about 10 μm to about 50 μm, fromabout 15 μm to about 85 μm, from about 5 μm to about 45 μm, or fromabout 15 μm to about 35 μm). K_(dv) can have a value of at most about3000, 2500, 2000, 1500, 1000, or 500. K_(dv) can have a value of atleast about 500, 1000, 1500, 2000, 2500, or 3000. K_(dv) can have anyvalue between the afore-mentioned values (e.g., from about 3000 to about500, from about 1000 to about 2500, from about 500 to about 2000, fromabout 1000 to about 3000, or from about 1000 to about 2500).

The system and/or apparatus can comprise a controlling mechanism (e.g.,a controller). The methods, systems, and/or apparatuses disclosed hereinmay incorporate a controller mechanism that controls one or more of thecomponents of the 3D printer described herein. The controller maycomprise a computer-processing unit (e.g., a computer) coupled to any ofthe systems and/or apparatuses, or their respective components (e.g.,the energy source(s)). The computer can be operatively coupled through awired and/or through a wireless connection. In some cases, the computercan be on board a user device. A user device can be a laptop computer,desktop computer, tablet, smartphone, or another computing device. Thecontroller can be in communication with a cloud computer system and/or aserver. The controller can be programmed to selectively direct theenergy source(s) to apply energy to the at least a portion of the targetsurface at a power per unit area. The controller can be in communicationwith the scanner configured to articulate the energy source(s) to applyenergy to at least a portion of the target surface at a power per unitarea.

The controller may control the layer dispensing mechanism and/or any ofits components. The controller may control the platform. The control maycomprise controlling (e.g., directing and/or regulating) the speed(velocity) of movement. The movement may be horizontal, vertical, and/orin an angle. The controller may control the level of pressure (e.g.,vacuum, ambient, or positive pressure) in the material removal mechanismmaterial dispensing mechanism, and/or the enclosure (e.g., chamber). Thepressure level (e.g., vacuum, ambient, or positive pressure) may beconstant or varied. The pressure level may be turned on and off manuallyand/or by the controller. The controller may control the forcegenerating mechanism. For example, the controller may control the amountof magnetic, electrical, pneumatic, and/or physical force generated byforce generating mechanism. For example, the controller may control thepolarity type of magnetic, and/or electrical charge generated by theforce generating mechanism. The controller may control the timing andthe frequency at which the force is generated. The controller maycontrol the direction and/or rate of movement of the translatingmechanism. The controller may control the cooling member (e.g., externaland/or internal). In some embodiments, the external cooling member maybe translatable. The movement of the layer dispensing mechanism or anyof its components may be predetermined. The movement of the layerdispensing mechanism or any of its components may be according to analgorithm. The control may be manual and/or automatic. The control maybe programmed and/or be effectuated a whim. The control may be accordingto an algorithm. The algorithm may comprise a printing algorithm, ormotion control algorithm. The algorithm may consider the model of the 3Dobject.

The controller may comprise a processing unit. The processing unit maybe central. The processing unit may comprise a central processing unit(herein “CPU”). The controllers or control mechanisms (e.g., comprisinga computer system) may be programmed to implement methods of thedisclosure. The controller may control at least one component of thesystems and/or apparatuses disclosed herein. FIG. 22 is a schematicexample of a computer system 2200 that is programmed or otherwiseconfigured to facilitate the formation of a 3D object per the methodsprovided herein. The computer system 2200 can control (e.g., directand/or regulate) various features of printing methods, apparatuses andsystems of the present disclosure, such as, for example, regulatingforce, translation, heating, cooling and/or maintaining the temperatureof a powder bed, process parameters (e.g., chamber pressure), scanningroute of the energy source, position and/or temperature of the coolingmember(s), application of the amount of energy emitted to a selectedlocation, or any combination thereof. The computer system 2201 can bepart of, or be in communication with, a printing system or apparatus,such as a 3D printing system or apparatus of the present disclosure. Thecomputer may be coupled to one or more mechanisms disclosed herein,and/or any parts thereof. For example, the computer may be coupled toone or more sensors, valves, switches, motors, pumps, or any combinationthereof.

Control may comprise regulate, monitor, restrict, limit, govern,restrain, supervise, direct, guide, manipulate, or modulate. Thecontroller can be operatively coupled to one or more of the apparatuses,system and/or their parts as disclosed herein. The controller and thecomputer system can be any of the one disclosed in patent applicationsSer. Nos. 62/297,067, 62/401,534, 62/252,330, 62/396,584, orPCT/US16/59781, all of which are fully incorporated herein by reference.

The computer system 2200 can include a processing unit 2206 (also“processor,” “computer” and “computer processor” used herein). Thecomputer system may include memory or memory location 2202 (e.g.,random-access memory, read-only memory, flash memory), electronicstorage unit 2204 (e.g., hard disk), communication interface 2203 (e.g.,network adapter) for communicating with one or more other systems, andperipheral devices 2205, such as cache, other memory, data storageand/or electronic display adapters. The memory 2202, storage unit 2204,interface 2203, and peripheral devices 2205 are in communication withthe processing unit 2206 through a communication bus (solid lines), suchas a motherboard. The storage unit can be a data storage unit (or datarepository) for storing data. The computer system can be operativelycoupled to a computer network (“network”) 2201 with the aid of thecommunication interface. The network can be the Internet, an Internetand/or extranet, or an intranet and/or extranet that is in communicationwith the Internet. The network in some cases is a telecommunicationand/or data network. The network can include one or more computerservers, which can enable distributed computing, such as cloudcomputing. The network, in some cases with the aid of the computersystem, can implement a peer-to-peer network, which may enable devicescoupled to the computer system to behave as a client or a server.

The processing unit can execute a sequence of machine-readableinstructions, which can be embodied in a program or software. Theinstructions may be stored in a memory location, such as the memory2202. The instructions can be directed to the processing unit, which cansubsequently program or otherwise configure the processing unit toimplement methods of the present disclosure. Examples of operationsperformed by the processing unit can include fetch, decode, execute, andwrite back. The processing unit may interpret and/or executeinstructions. The processor may include a microprocessor, a dataprocessor, a central processing unit (CPU), a graphical processing unit(GPU), a system-on-chip (SOC), a co-processor, a network processor, anapplication specific integrated circuit (ASIC), an application specificinstruction-set processor (ASIPs), a controller, a programmable logicdevice (PLD), a chipset, a field programmable gate array (FPGA), or anycombination thereof. The processing unit can be part of a circuit, suchas an integrated circuit. One or more other components of the system2200 can be included in the circuit.

The storage unit 2204 can store files, such as drivers, libraries andsaved programs. The storage unit can store user data, e.g., userpreferences and user programs. The computer system in some cases caninclude one or more additional data storage units that are external tothe computer system, such as located on a remote server that is incommunication with the computer system through an intranet or theInternet.

The computer system can communicate with one or more remote computersystems through the network. For instance, the computer system cancommunicate with a remote computer system of a user (e.g., operator).Examples of remote computer systems include personal computers (e.g.,portable PC), slate or tablet PC's (e.g., Apple® iPad, Samsung® GalaxyTab), telephones, Smart phones (e.g., Apple® iPhone, Android-enableddevice, Blackberry®), or personal digital assistants. The user canaccess the computer system via the network.

Methods as described herein can be implemented by way of machine (e.g.,computer processor) executable code stored on an electronic storagelocation of the computer system, such as, for example, on the memory2202 or electronic storage unit 2204. The machine executable ormachine-readable code can be provided in the form of software. Duringuse, the processor 2206 can execute the code. In some cases, the codecan be retrieved from the storage unit and stored on the memory forready access by the processor. In some situations, the electronicstorage unit can be precluded, and machine-executable instructions arestored on memory.

The code can be pre-compiled and configured for use with a machine havea processor adapted to execute the code, or can be compiled duringruntime. The code can be supplied in a programming language that can beselected to enable the code to execute in a pre-compiled or as-compiledfashion.

The processing unit may include one or more cores. The computer systemmay comprise a single core processor, multi core processor, or aplurality of processors for parallel processing. The processing unit maycomprise one or more central processing unit (CPU) and/or a graphicprocessing unit (GPU). The multiple cores may be disposed in a physicalunit (e.g., Central Processing Unit, or Graphic Processing Unit). Theprocessing unit may include one or more processing units. The physicalunit may be a single physical unit. The physical unit may be a die. Thephysical unit may comprise cache coherency circuitry. The multiple coresmay be disposed in close proximity. The physical unit may comprise anintegrated circuit chip. The integrated circuit chip may comprise one ormore transistors. The integrated circuit chip may comprise at least 0.2billion transistors (BT), 0.5 BT, 1 BT, 2 BT, 3 BT, 5 BT, 6 BT, 7 BT, 8BT, 9 BT, 10 BT, 15 BT, 20 BT, 25 BT, 30 BT, 40 BT, or 50 BT. Theintegrated circuit chip may comprise at most 7 BT, 8 BT, 9 BT, 10 BT, 15BT, 20 BT, 25 BT, 30 BT, 40 BT, 50 BT, 70 BT, or 100 BT. The integratedcircuit chip may comprise any number of transistors between theafore-mentioned numbers (e.g., from about 0.2 BT to about 100 BT, fromabout 1 BT to about 8 BT, from about 8 BT to about 40 BT, or from about40 BT to about 100 BT). The integrated circuit chip may have an area ofat least 50 mm², 60 mm², 70 mm², 80 mm², 90 mm², 100 mm², 200 mm², 300mm², 400 mm², 500 mm², 600 mm², 700 mm², or 800 mm². The integratedcircuit chip may have an area of at most 50 mm², 60 mm², 70 mm², 80 mm²,90 mm², 100 mm², 200 mm², 300 mm², 400 mm², 500 mm², 600 mm², 700 mm²,or 800 mm². The integrated circuit chip may have an area of any valuebetween the afore-mentioned values (e.g., from about 50 mm² to about 800mm², from about 50 mm² to about 500 mm², or from about 500 mm² to about800 mm²). The close proximity may allow substantial preservation ofcommunication signals that travel between the cores. The close proximitymay diminish communication signal degradation. A core as understoodherein is a computing component having independent central processingcapabilities. The computing system may comprise a multiplicity of cores,which are disposed on a single computing component. The multiplicity ofcores may include two or more independent central processing units. Theindependent central processing units may constitute a unit that read andexecute program instructions. The multiplicity of cores can be parallelcores. The multiplicity of cores can function in parallel. Themultiplicity of cores may include at least 2, 10, 40, 100, 400, 1000,2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, or 10000 cores. Themultiplicity of cores may include at most 1000, 2000, 3000, 4000, 5000,6000, 7000, 8000, 9000, 10000, or 40000 cores. The multiplicity of coresmay include cores of any number between the afore-mentioned numbers(e.g., from 2 to 40000, from 2 to 400, from 400 to 4000, from 2000 to4000, or from 4000 to 10000 cores). The processor may comprise lowlatency in data transfer (e.g., from one core to another). Latency mayrefer to the time delay between the cause and the effect of a physicalchange in the processor (e.g., a signal). Latency may refer to the timeelapsed from the source (e.g., first core) sending a packet to thedestination (e.g., second core) receiving it (also referred as two-pointlatency). One point latency may refer to the time elapsed from thesource (e.g., first core) sending a packet (e.g., signal) to thedestination (e.g., second core) receiving it, and the designationsending a packet back to the source (e.g., the packet making a roundtrip). The latency may be sufficiently low to allow a high number offloating point operations per second (FLOPS). The number of FLOPS may beat least about 1 Tera Flops (T-FLOPS), 2 T-FLOPS, 3 T-FLOPS, 5 T-FLOPS,6 T-FLOPS, 7 T-FLOPS, 8 T-FLOPS, 9 T-FLOPS, or 10 T-FLOPS. The number offlops may be at most about 5 T-FLOPS, 6 T-FLOPS, 7 T-FLOPS, 8 T-FLOPS, 9T-FLOPS, 10 T-FLOPS, 20 T-FLOPS, or 30 T-FLOPS. The number of FLOPS maybe any value between the afore-mentioned values (e.g., from about 1T-FLOP to about 30 T-FLOP, from about 4 T-FLOPS to about 10 T-FLOPS,from about 1 T-FLOPS to about 10 T-FLOPS, or from about 10 T-FLOPS toabout 30 T-FLOPS. The FLOPS can be measured according to a benchmark.The benchmark may be a HPC Challenge Benchmark. The benchmark maycomprise mathematical operations (e.g., equation calculation such aslinear equations), graphical operations (e.g., rendering), orencryption/decryption benchmark. The benchmark may comprise a HighPerformance UNPACK, matrix multiplication (e.g., DGEMM), sustainedmemory bandwidth to/from memory (e.g., STREAM), array transposing ratemeasurement (e.g., PTRANS), RandomAccess, rate of Fast Fourier Transform(e.g., on a large one-dimensional vector using the generalizedCooley-Tukey algorithm), or Communication Bandwidth and Latency (e.g.,MPI-centric performance measurements based on the effectivebandwidth/latency benchmark). UNPACK refers to a software library forperforming numerical linear algebra on a digital computer. DGEMM refersto double precision general matrix multiplication. STREAM. PTRANS. MPIrefers to Message Passing Interface.

The computer system may include hyper-threading technology. The computersystem may include a chip processor with integrated transform, lighting,triangle setup, triangle clipping, rendering engine, or any combinationthereof. The rendering engine may be capable of processing at leastabout 10 million polygons per second. The rendering engines may becapable of processing at least about 10 million calculations per second.As an example, the GPU may include a GPU by Nvidia, ATI Technologies, S3Graphics, Advanced Micro Devices (AMD), or Matrox. The processing unitmay be able to process algorithms comprising a matrix or a vector. Thecore may comprise a complex instruction set computing core (CISC), orreduced instruction set computing (RISC).

The computer system may include an electronic chip that isreprogrammable (e.g., field programmable gate array (FPGA)). Forexample, the FPGA may comprise Tabula, Altera, or Xilinx FPGA. Theelectronic chips may comprise one or more programmable logic blocks(e.g., an array). The logic blocks may compute combinational functions,logic gates, or any combination thereof. The computer system may includecustom hardware. The custom hardware may comprise an algorithm.

The computer system may include configurable computing, partiallyreconfigurable computing, reconfigurable computing, or any combinationthereof. The computer system may include a FPGA. The computer system mayinclude an integrated circuit that performs the algorithm. For example,the reconfigurable computing system may comprise FPGA, CPU, GPU, ormulti-core microprocessors. The reconfigurable computing system maycomprise a High-Performance Reconfigurable Computing architecture(HPRC). The partially reconfigurable computing may include module-basedpartial reconfiguration, or difference-based partial reconfiguration.

The computing system may include an integrated circuit that performs thealgorithm (e.g., control algorithm). The physical unit (e.g., the cachecoherency circuitry within) may have a clock time of at least about 0.1Gigabits per second (Gbit/s), 0.5 Gbit/s, 1 Gbit/s, 2 Gbit/s, 5 Gbit/s,6 Gbit/s, 7 Gbit/s, 8 Gbit/s, 9 Gbit/s, 10 Gbit/s, or 50 Gbit/s. Thephysical unit may have a clock time of any value between theafore-mentioned values (e.g., from about 0.1 Gbit/s to about 50 Gbit/s,or from about 5 Gbit/s to about 10 Gbit/s). The physical unit mayproduce the algorithm output in at most 0.1 microsecond (μs), 1 μs, 10μs, 100 μs, or 1 millisecond (msec). The physical unit may produce thealgorithm output in any time between the above-mentioned times (e.g.,from about 0.1 μs, to about 1 msec, from about 0.1 μs, to about 100 μs,or from about 0.1 μs to about 10 μs). In some instances, the controllermay use calculations, real time measurements, or any combination thereofto regulate the energy beam(s). In some instances, the real-timemeasurements (e.g., temperature measurements) may provide input at arate of at least about 0.1 KHz, 1 KHz, 10 KHz, 100 KHz, 1000 KHz, or10000 KHz). In some instances, the real-time measurements may provideinput at a rate between any of the above-mentioned rates (e.g., fromabout 0.1 KHz to about 10000 KHz, from about 0.1 KHz to about 1000 KHz,or from about 1000 KHz to about 10000 KHz). The memory bandwidth of theprocessing unit may be at least about 1 gigabytes per second (Gbytes/s),10 Gbytes/s, 100 Gbytes/s, 200 Gbytes/s, 300 Gbytes/s, 400 Gbytes/s, 500Gbytes/s, 600 Gbytes/s, 700 Gbytes/s, 800 Gbytes/s, 900 Gbytes/s, or1000 Gbytes/s. The memory bandwidth of the processing unit may be atmost about 1 gigabytes per second (Gbytes/s), 10 Gbytes/s, 100 Gbytes/s,200 Gbytes/s, 300 Gbytes/s, 400 Gbytes/s, 500 Gbytes/s, 600 Gbytes/s,700 Gbytes/s, 800 Gbytes/s, 900 Gbytes/s, or 1000 Gbytes/s. The memorybandwidth of the processing unit may any value between theafore-mentioned values (e.g., from about 1 Gbytes/s to about 1000Gbytes/s, from about 100 Gbytes/s to about 500 Gbytes/s, from about 500Gbytes/s to about 1000 Gbytes/s, or from about 200 Gbytes/s to about 400Gbytes/s).

Aspects of the systems, apparatuses, and/or methods provided herein,such as the computer system, can be embodied in programming. Variousaspects of the technology may be thought of as “product,” “object,” or“articles of manufacture” typically in the form of machine (orprocessor) executable code and/or associated data that is carried on orembodied in a type of machine-readable medium. Machine-executable codecan be stored on an electronic storage unit, such memory (e.g.,read-only memory, random-access memory, flash memory) or a hard disk.The storage may comprise non-volatile storage media. “Storage” typemedia can include any or all of the tangible memory of the computers,processors or the like, or associated modules thereof, such as varioussemiconductor memories, tape drives, disk drives, external drives, andthe like, which may provide non-transitory storage at any time for thesoftware programming.

The memory may comprise a random-access memory (RAM), dynamic randomaccess memory (DRAM), static random access memory (SRAM), synchronousdynamic random access memory (SDRAM), ferroelectric random access memory(FRAM), read only memory (ROM), programmable read only memory (PROM),erasable programmable read only memory (EPROM), electrically erasableprogrammable read only memory (EEPROM), a flash memory, or anycombination thereof. The flash memory may comprise a negative-AND (NAND)or NOR logic gates. The storage may include a hard disk (e.g., amagnetic disk, an optical disk, a magneto-optic disk, a solid-statedisk, etc.), a compact disc (CD), a digital versatile disc (DVD), afloppy disk, a cartridge, a magnetic tape, and/or another type ofcomputer-readable medium, along with a corresponding drive.

All or portions of the software may at times be communicated through theInternet or various other telecommunication networks. Suchcommunications, for example, may enable loading of the software from onecomputer or processor into another, for example, from a managementserver or host computer into the computer platform of an applicationserver. Thus, another type of media that may bear the software elementsincludes optical, electrical and electromagnetic waves, such as usedacross physical interfaces between local devices, through wired andoptical landline networks and over various air-links. The physicalelements that carry such waves, such as wired or wireless links, opticallinks, or the like, also may be considered as media bearing thesoftware. As used herein, unless restricted to non-transitory, tangible“storage” media, terms such as computer or machine “readable medium”refer to any medium that participates in providing instructions to aprocessor for execution.

Hence, a machine-readable medium, such as computer-executable code, maytake many forms, including but not limited to, a tangible storagemedium, a carrier wave medium, or physical transmission medium.Non-volatile storage media include, for example, optical or magneticdisks, such as any of the storage devices in any computer(s) or thelike, such as may be used to implement the databases, etc. shown in thedrawings. Volatile storage media include dynamic memory, such as mainmemory of such a computer platform. Tangible transmission media includecoaxial cables, wire (e.g., copper wire), and/or fiber optics, includingthe wires that comprise a bus within a computer system. Carrier-wavetransmission media may take the form of electric or electromagneticsignals, or acoustic or light waves such as those generated during radiofrequency (RF) and infrared (IR) data communications. Common forms ofcomputer-readable media therefore include for example: a floppy disk, aflexible disk, hard disk, magnetic tape, any other magnetic medium, aCD-ROM, DVD or DVD-ROM, any other optical medium, punch cards papertape, any other physical storage medium with patterns of holes, a RAM, aROM, a PROM and EPROM, a FLASH-EPROM, any other memory chip orcartridge, a carrier wave transporting data or instructions, cables orlinks transporting such a carrier wave, or any other medium from which acomputer may read programming code and/or data. The memory and/orstorage may comprise a storing device external to and/or removable fromdevice, such as a Universal Serial Bus (USB) memory stick, or a harddisk. Many of these forms of computer readable media may be involved incarrying one or more sequences of one or more instructions to aprocessor for execution.

The computer system can include or be in communication with anelectronic display that comprises a user interface (UI) for providing,for example, a model design or graphical representation of a 3D objectto be printed. Examples of UI's include, without limitation, a graphicaluser interface (GUI) and web-based user interface. The computer systemcan monitor and/or control various aspects of the 3D printing system.The control may be manual and/or programmed. The control may rely onfeedback mechanisms that have been pre-programmed. The feedbackmechanisms may rely on input from sensors (described herein) that areconnected to the control unit (i.e., control system or control mechanisme.g., computer). The computer system may store historical dataconcerning various aspects of the operation of the 3D printing system.The historical data may be retrieved at predetermined times and/or at awhim. The historical data may be accessed by an operator and/or by auser. The historical and/or operative data may be provided in an outputunit such as a display unit. The output unit (e.g., monitor) may outputvarious parameters of the 3D printing system (as described herein) inreal time or in a delayed time. The output unit may output the current3D printed object, the ordered 3D printed object, or both. The outputunit may output the printing progress of the 3D printed object. Theoutput unit may output at least one of the total time, time remaining,and time expanded on printing the 3D object. The output unit may output(e.g., display, voice, and/or print) the status of sensors, theirreading, and/or time for their calibration or maintenance. The outputunit may output the type of material(s) used and various characteristicsof the material(s) such as temperature and flowability of thepre-transformed material. The output unit may output the amount ofoxygen, water, and pressure in the printing chamber (i.e., the chamberwhere the 3D object is being printed). The computer may generate areport comprising various parameters of the 3D printing system, method,and or objects at predetermined time(s), on a request (e.g., from anoperator), and/or at a whim. The output unit may comprise a screen,printer, or speaker. The control system may provide a report. The reportmay comprise any items recited as optionally output by the output unit.

The system and/or apparatus described herein (e.g., controller) and/orany of their components may comprise an output and/or an input device.The input device may comprise a keyboard, touch pad, or microphone. Theoutput device may be a sensory output device. The output device mayinclude a visual, tactile, or audio device. The audio device may includea loudspeaker. The visual output device may include a screen and/or aprinted hard copy (e.g., paper). The output device may include aprinter. The input device may include a camera, a microphone, akeyboard, or a touch screen. The system and/or apparatus describedherein (e.g., controller) and/or any of their components may compriseBluetooth technology. The system and/or apparatus described herein(e.g., controller) and/or any of their components may comprise acommunication port. The communication port may be a serial port or aparallel port. The communication port may be a Universal Serial Bus port(i.e., USB). The system and/or apparatus described herein (e.g.,controller) and/or any of their components may comprise USB ports. TheUSB can be micro or mini USB. The USB port may relate to device classescomprising 00h, 01h, 02h, 03h, 05h, 06h, 07h, 08h, 09h, 0Ah, 0Bh, 0Dh,0Eh, 0Fh, 10h, 11h, DCh, E0h, EFh, FEh, or FFh. The system and/orapparatus described herein (e.g., controller) and/or any of theircomponents may comprise a plug and/or a socket (e.g., electrical, ACpower, DC power). The system and/or apparatus described herein (e.g.,controller) and/or any of their components may comprise an adapter(e.g., AC and/or DC power adapter). The system and/or apparatusdescribed herein (e.g., controller) and/or any of their components maycomprise a power connector. The power connector can be an electricalpower connector. The power connector may comprise a magnetically coupled(e.g., attached) power connector. The power connector can be a dockconnector. The connector can be a data and power connector. Theconnector may comprise pins. The connector may comprise at least 10, 15,18, 20, 22, 24, 26, 28, 30, 40, 42, 45, 50, 55, 80, or 100 pins.

The systems, methods, and/or apparatuses disclosed herein may comprisereceiving a request for a 3D object (e.g., from a customer). The requestcan include a model (e.g., CAD) of the desired 3D object. Alternativelyor additionally, a model of the desired 3D object may be generated. Themodel may be used to generate 3D printing instructions. The 3D printinginstructions may exclude the 3D model. The 3D printing instructions maybe based on the 3D model. The 3D printing instructions may take the 3Dmodel into account. The 3D printing instructions may be based onsimulations. The 3D printing instructions may use the 3D model. The 3Dprinting instructions may comprise using an algorithm (e.g., embedded ina software) that considers the 3D model. The algorithm may considering adeviation from the model. The deviation may be a corrective deviation.The corrective deviation may be such that at least a portion of the 3Dobject is printed as a deviation from the 3D model, and upon hardening,the at least a portion of the 3D object (and/or the entire 3D object)will not substantially deviate from the model of the desired 3D object.The printing instructions may be used to print the desired 3D object.The printed 3D object may substantially correspond to the requested 3Dobject. In some embodiments, the algorithm used to form the 3D printinginstructions excludes a feedback control loop (e.g., closed loop). 3Dprinting instructions may exclude considering metrology measurements ofthe generated 3D object (e.g., measurements of the 3D object) or partsthereof. In some embodiments, the 3D printing instructions may comprisean open loop control. The algorithm may use historical (e.g., empirical)data. The empirical data may be of characteristic structures (e.g., thatare included in the desired 3D object). The characteristic structuresmay be substantially similar at least portions of the 3D object. Theempirical data may be previously obtained. In some embodiments, thealgorithm may use a theoretical model. The algorithm may use a model ofenergy flow (e.g., heat flow). The generation of the 3D object using analtered model may exclude an iterative process. The generation of the 3Dobject may not involve an alteration of the 3D model (e.g., CAD), butrather generate a new set of 3D printing instructions. In someembodiments, the algorithm is used to alter instructions received by atleast one of the components involved in the 3D printing process (e.g.,energy beam). In some embodiments, the algorithm does not alter the 3Dmodel. The algorithm may comprise a generic approach to printing adesired 3D object or portions thereof. In some embodiments, thealgorithm is not based on altering 3D printing instructions that arebased on printing the desired 3D object, measuring errors in the printed3D object, and revising the printing instructions. In some embodiments,the algorithm is not based on an iterative process that considers thedesired and printed 3D object (e.g., in real-time). The algorithm may bebased on an estimation of one or more errors during the printing of thedesired 3D object. The algorithm may be based on correct the estimatederrors through the generation of respective 3D printing instructionsthat considers the anticipated errors. In this manner, the algorithm maycircumvent the generation of the errors. The algorithm may be based onan estimation of one or more errors during the printing of the desired3D object, and correcting them through the generation of respective 3Dprinting instructions that considers the anticipated errors and thuscircumvent the generation of the errors. The error may comprise thedeviation from the model of the desired 3D object. The estimation may bebased on simulation, modeling, and/or historical data (e.g., ofrepresentative structures or structure segments). FIG. 23 shows anexample of a flow chart representing the 3D printing process steps thatare executed by a 3D printing system and/or apparatus described herein.The desired 3D object is requested in step 2301. A 3D model is providedor generated in step 2302. Step 2304 illustrates the generation ofprinting instructions for the 3D object, in which both the model and thealgorithm are utilized. The 3D object is subsequently generated usingthe printing instructions in step 2305. The desired 3D object isdelivered in step 2306. Arrow 2307 designates the direction of theexecution of the steps from step 2301 to step 2306. The absence of backfeeding arrow represents the lack of feedback loop control.

EXAMPLES

The following are illustrative and non-limiting examples of methods ofthe present disclosure.

Example 1

In a 25 cm by 25 cm by 30 cm container at ambient temperature andpressure, Inconel 718 powder of average particle size 32 μm is depositedin a container accommodating a powder bed. The container is disposed inan enclosure at ambient temperature and pressure. The enclosure ispurged with Argon gas (Ar) for 5 min. Above the exposed surface of thepowder bed, a planar layer of powder material with an average height of0.05 mm was placed in the container accommodating a powder bed. A 200 Wfiber 1060 nm laser beam fabricated a substantially flat surface thatwas anchorlessly suspended in the powder bed as follows: The exposedsurface of the powder bed was irradiated with a defocused Gaussian spotof cross section diameter 0.4 mm for about 100 milliseconds to form afirst tile of molten powder. After forming the first tile, the laserbeam moved away to another spot on the powder bed that was far away fromthe tile. After more than 5 seconds (e.g., the intermission), the laserbeam returned to the vicinity of the first tile, to form a second tileof molten powder. During the intermission, the molten material of thefirst tile cooled down. The distance between the centers of the firstand second tiles ranges from about 0.1 mm to about 0.2 mm, formingoverlapping tiles. The rectangular 3D object having one layer wasfabricated by successively forming such tiles. The rectangular 3D object(box) measured 8 mm by 20 mm having a high as depicted in FIG. 39A. The3D object was vertically cross sectioned, and a portion of its verticalcross section was imaged by a 2 Mega pixel charge-coupled device (CCD)camera, which portion of its vertical cross section is shown in theexample in FIG. 39A.

Example 2

Following the layer formed in Example 1, a second planar layer of powdermaterial was deposited on the exposed surface of the powder bed(comprising the one layered 3D object), at ambient temperature andpressure, under Argon. The deposited planar powder layer had an averageheight of 0.05. The 200 W fiber 1060 nm laser beam fabricated asubstantially flat surface on the first layer in Example 1, to form asecond layer as part of the 3D object, which 3D object was anchorlesslysuspended in the powder bed as described above for forming the firstlayer. The rectangular 3D object was fabricated by successively formingsuch tiles. A portion of the second layer deposited on the first layeris shown in the top view of FIG. 30, 3050. Tiles forming the secondlayer are shown in 3070, which second layer is disposed on the firstlayer 3060. The rectangular 3D object (box) measured 8 mm by 20 mmhaving a high as depicted in FIG. 39A. The 3D object was verticallycross sectioned, and portion of its vertical cross section was imaged bythe 2 Mega pixel CCD camera, which portion of its vertical cross sectionis shown in the example in FIG. 39B.

Example 3

Following the layer formed in Example 2, a third planar layer of powdermaterial was deposited on the exposed surface of the powder bed(comprising the one layered 3D object), at ambient temperature andpressure, under Argon. The deposited planar powder layer had an averageheight of 0.05. The 200 W fiber 1060 nm laser beam fabricated asubstantially flat surface on the second layer in Example 2, to form athird layer as part of the 3D object, which 3D object was anchorlesslysuspended in the powder bed as described above for forming the secondand first layer. The rectangular 3D object was fabricated bysuccessively forming such tiles. The rectangular 3D object (box)measured 8 mm by 20 mm having a high as depicted in FIG. 36. The 3Dobject was vertically cross sectioned, and a portion of its verticalcross section was imaged by the 2 Mega pixel CCD camera, which portionof its vertical cross section is shown in the example in FIG. 36, 3610.

While preferred embodiments of the present invention have been shown,and described herein, it will be obvious to those skilled in the artthat such embodiments are provided by way of example only. It is notintended that the invention be limited by the specific examples providedwithin the specification. While the invention has been described withreference to the afore-mentioned specification, the descriptions andillustrations of the embodiments herein are not meant to be construed ina limiting sense. Numerous variations, changes, and substitutions willnow occur to those skilled in the art without departing from theinvention. Furthermore, it shall be understood that all aspects of theinvention are not limited to the specific depictions, configurations, orrelative proportions set forth herein which depend upon a variety ofconditions and variables. It should be understood that variousalternatives to the embodiments of the invention described herein may beemployed in practicing the invention. It is therefore contemplated thatthe invention shall also cover any such alternatives, modifications,variations, or equivalents. It is intended that the following claimsdefine the scope of the invention and that methods and structures withinthe scope of these claims and their equivalents be covered thereby.

What is claimed is:
 1. A method for printing a three-dimensional object,comprising: (A) providing a first pre-transformed material to a bottomskin layer of hardened material that is disposed above a platform, whichbottom skin layer is part of the three-dimensional object; and (B) usingan energy beam to: (I) transform the pre-transformed material to a firstportion of transformed material as part of the three-dimensional object,which first portion has a first lateral cross section, (II) increase atemperature of a second portion that (a) is part of the bottom skinlayer and (b) has a second lateral cross section that at least partiallyoverlaps the first lateral cross section, to at least a targettemperature value that is at least one of (i) above the solidustemperature and below the liquidus temperature of the material of thebottom skin layer, and (ii) at a temperature at which the material ofthe bottom skin layer in the second portion plastically yields.
 2. Themethod of claim 1, wherein a center of the first cross section is abovethe second cross section.
 3. The method of claim 1, wherein the bottomskin layer of hardened material is disposed above the platform along adirection perpendicular to the platform.
 4. The method of claim 1,wherein the temperature of the second portion is increased with the aidof a simulation.
 5. The method of claim 4, wherein the simulationcomprises a temperature or mechanical simulation of printing thethree-dimensional object.
 6. The method of claim 4, wherein thesimulation comprises thermo-mechanical simulation.
 7. The method ofclaim 4, wherein the simulation comprises a material property of thethree-dimensional object.
 8. The method of claim 4, wherein thetemperature of the second portion is increased with the aid of agraphical processing unit (GPU), system-on-chip (SOC), applicationspecific integrated circuit (ASIC), application specific instruction-setprocessor (ASIPs), programmable logic device (PLD), or fieldprogrammable gate array (FPGA).
 9. A method for printing athree-dimensional object, comprising: (A) providing a material bedcomprising a pre-transformed material and a bottom skin layer ofhardened material, which material bed is disposed above a platform,wherein the bottom skin layer is part of the three-dimensional object,wherein at least a fraction of the pre-transformed material is disposedabove the bottom skin layer; and (B) irradiating a first portion of theplanar layer with the energy beam to: (I) transform the pre-transformedmaterial in the first portion to a transformed material as part of thethree-dimensional object, which first portion has a first lateral crosssection; (II) increase a temperature of a second portion that (a) ispart of the bottom skin layer and (b) has a second lateral cross sectionthat overlaps the first lateral cross section, to at least a targettemperature value that is at least one of (i) above the solidustemperature and below the liquidus temperature of the material of thebottom skin layer, and (ii) at a temperature at which the material ofthe bottom skin layer in the second portion plastically yields.
 10. Themethod of claim 9, wherein the temperature of the second portion isincreased using feedback or feed-forward control.
 11. The method ofclaim 9, wherein the temperature of the second portion is increasedusing closed loop or open loop control.
 12. The method of claim 11,wherein the control comprises using a graphical processing unit (GPU),system-on-chip (SOC), application specific integrated circuit (ASIC),application specific instruction-set processor (ASIPs), programmablelogic device (PLD), or field programmable gate array (FPGA).
 13. Themethod of claim 9, wherein providing the material bed comprisesdispensing a layer of the pre-transformed material by removing an excessof pre-transformed material from the exposed surface of the material bedusing gas flow and cyclonically separating the pre-transformed materialfrom the gas flow.
 14. A method for printing a three-dimensional object,comprising: (a) providing a pre-transformed material to a bottom skinlayer of hardened material disposed above a platform, wherein the bottomskin layer is part of the three-dimensional object; (b) using an energybeam to transform a portion of the pre-transformed material to a portionof transformed material disposed above the bottom skin layer; and (c)setting at least one characteristic of the energy beam such that atemperature of the three-dimensional object at the bottom skin layerbelow the portion of transformed material is at least one of (i) abovethe solidus temperature and below the liquidus temperature of thematerial of the bottom skin layer, and (ii) at temperature at which amaterial of the bottom skin layer plastically yields.
 15. The method ofclaim 14, wherein the transformed material is a melt pool.
 16. Themethod of claim 14, further comprising repeating (b) subsequent to (c).17. The method of claim 14, wherein the bottom skin layer is below theportion of transformed along a direction perpendicular to the platform.18. The method of claim 14, wherein the at least one characteristicscomprises power density, cross sectional area, trajectory, speed, focus,energy profile, dwell time, intermission time, or fluence of the energybeam.
 19. The method of claim 14, wherein the pre-transformed materialcomprises a particulate material formed of at least one member selectedfrom the group consisting of elemental metal, metal alloy, ceramic, andan allotrope of elemental carbon.
 20. A method for printing athree-dimensional object, comprising: (a) providing a material bedcomprising a pre-transformed material and a bottom skin layer ofhardened material, which material bed is disposed above a platform,wherein the bottom skin layer is part of the three-dimensional object,wherein at least a fraction of the pre-transformed material is disposedabove the bottom skin layer, wherein above is along a direction oppositeto the platform; (b) using an energy beam to transform a portion of atleast a fraction of the pre-transformed material into a transformedmaterial as part of the three-dimensional object; and (c) setting atleast one characteristic of the energy beam such that a temperature ofthe three-dimensional object at the bottom skin layer below the portionis at least one of (i) above the solidus temperature and below theliquidus temperature of the bottom skin layer material, and (ii) attemperature at which a material in the bottom skin layer plasticallyyields.
 21. The method of claim 20, wherein the bottom skin layer is afirst formed layer of (i) the three-dimensional object, (ii) a hangingstructure of the three-dimensional object, or (iii) a cavity ceiling ofthe three-dimensional object.
 22. The method of claim 21, wherein thebottom skin layer has a sphere of radius XY on a bottom surface of thebottom skin layer, wherein an acute angle between the straight line XYand the direction normal to the average layering plane of the bottomskin layer is in the range from about 45 degrees to about 90 degrees.23. The method of claim 22, wherein during printing, the first formedlayer of the three-dimensional object comprises auxiliary supportfeatures spaced apart by 2 millimeters or more.
 24. The method of claim22, wherein the hanging structure of the three-dimensional object has atleast one side that is disconnected from the three-dimensional object orthe platform.
 25. The method of claim 22, wherein the hanging structurecomprises auxiliary support features that are spaced apart by 2millimeters or more.
 26. The method of claim 22, wherein the cavityceiling of the three-dimensional object has at least one side that isdisconnected from the three-dimensional object or the platform.
 27. Themethod of claim 22, wherein the hanging structure comprises auxiliarysupports that are spaced apart by 2 millimeters or more.